play the computer-3 hard ..... You will not lose many rating points when you lose but you will learn a lot then evenually beat it. However saying that I am only around 1250 myself but I only played a few hundred games. You will get better if you do this and will not fall for tricks and strategies that others with better ratings use on you.
how to improve from 1200 rating

You have taken the first step towards smashing through that wall. Read Chirnov's Logical Chess Move by Move and Silman's Endgame Course. They most certainly do make those mistakes, but you need the tactical vision to spot them. I played a real 1550 OTB (admittedly only 20 minutes per side and unrated) and got two bishops vs. rook against him as he hoped for Nxe5-Rxe5-f4-Re8-e5, but I played Rxg5 winning knight and bishop for rook instead.

It seems most of your games are blitz games. These help you improve a little, but not nearly as much as if you play slower games.
If you want to improve here are some things you could do:
- Play slower games. With a longer time control you can learn to calculate and evaluate well, and you will not be rushed to guess moves
- Read a chess book. Irving Chernov's Logical Chess: Move by Move has already been mentioned and is a very good book for beginners
- Solve tactics. I recommend using 365chess.com because it doesn't have a timer. These will help you a lot.
All the best!
keep playing long games and remember under 1800 the better the analyst the better.
Right now I am currently trying to go 6 ply (three moves) ahead for Checks Captures and Threats on every single move. I think that at our level we lose due to lazy generalizations without calculation.
I get about 3 ply on every move and sometimes 4 or 5 ply; but this is as a very positional player for my rating meaning i do not go for cheap shots. So in summary get rid of bad habits and calculate your checks captures and threats each move

* Tactics Trainer every day.
* Read Heisman's "Back to Basics: Tactics"
* Read Logical Chess: Move by Move for basic positional and strategic planning

I already have around 1,000 games in the 1100-1200 rating..
I see a lot of players with 3k+ and 4k+ games that are stuck at this rating.. I am afraid if i just continue to play i will become like them, stuck more or less in the same rating.
I have not improved much since reaching 1200.
It was easier to win before because people make obvious mistakes like losing a piece.
The problem is at 1250+ people don't make big plunders like losing a hanging piece. And they usually calculate a few moves ahead, even if it's not the best strategically..
But no big blunders and thinking ahead a couple moves makes it really hard to win.
I feel like i will just keep playing and stay stuck at 1250 and just amount 5k games and never improve.
Any suggestions on how to progress from here?
You play blitz and bullet on chess.com that is the problem. Has to be the toughtest place to play as many can play 50-100 games easy without getting tired at all.
One word PRACTICE! Spend 20-30 minutes playing a game or reviewing a GM game. Learn how to play the End Game better. Mating patterns would help for sure. Review your games you lost. What your opponents strategy in the game ..... will it work on somebody else? That alone should bring you to 1350 depending on how much time you put into it.
Well you hit it on the nose. Quality over crap. Anybody can take advantage of error by an opponent. Learn how to create a weakness in their area of the board. Learn how to open up diagonals and files that favor you and not your opponent. Try to keep them closed if your opponent tries this. If they have no path to march their army then how are they going to threaten your king.

I hear you man. I was at the 1200 level for a while. I felt like I could beat all my friends and family, but against higher level of competition of people that actually played chess decently I got crushed.
1200s from what I observed really don't play sound fundamental chess. Although they know the fundamentals they haven't really appreciated it I think. Also, this sound counter intuitive but I would try playing non-gambits and switch it up, this way you get to hone in your fundamentals and get past this elo trap then you can go back and play gambits once your past this level.
I put together a detailed guide on kind of what to expect at each elo level check it out.
From a 500 ELO Beginner to a 2000 ELO Expert
https://www.chess.com/forum/view/chess-players/from-a-500-elo-beginner-to-a-2000-elo-expert

Read some books like Logical Chess, move by move.
Learn a few basic openings, and run ALL of your games through the engine, and if you can't (because you aren't a prem member), the self analysis works as well, or you can go to the L-chess website and use their free stockfish 8. Use the engine to check for missed tactics, wins, etc.
In know this sounds bad: If you want to get better, I would recommend a few things.
1. Use an engine to help you play your games on a site that allows it. (NOT Chess.com). I played with an engine on sparkchess.com for a while and it helped me improve. Watching how the engine plays its moves will help you learn why and also implement these ideas into your own games. You can play the opening by yourself and then let the engine play the rest of the game if you have a stockfish engine like I do.
2. When analyzing your own games from chess.com, it will tell you the accuracy of your moves in each area of the game. Find some books that help you on the area you struggle in. Look at databases if it is the opening. I recommend Jeremy Silman's "Improve your chess by mastering the Imbalances" 4th edition for the middle-game. Read basic endgame manuals to understand the basics of endgames.
3. Get better at finding weaknesses in your opponent's position and targeting them. Also pay more attention to what your opponent is doing instead of just following your own plan oblivious of what your opponent can do to counter it. ALWAYS assume your opponent will find the best reply to your move so don't do something risky if you know it won't work.
4. I recommend longer games to play since it will develop your calculation abilities which will be helpful in shorter games once mastered.
5. The 1200 range usually struggles with advanced tactics and positional play. Watch GM's as they play their games and see how they move their pieces to better squares. Take advantage of open diagonals and important squares. Also, get better at tactics - This will help you not fall for them yourself and also will help you spot them when your opponent messes up.
its amazing to watch Hikaru play and see how many moves he sees that are good moves and there's way more than one move in any position that are good moves ... arrows all over the place

I hear you man. I was at the 1200 level for a while. I felt like I could beat all my friends and family, but against higher level of competition of people that actually played chess decently I got crushed.
1200s from what I observed really don't play sound fundamental chess. Although they know the fundamentals they haven't really appreciated it I think. Also, this sound counter intuitive but I would try playing non-gambits and switch it up, this way you get to hone in your fundamentals and get past this elo trap then you can go back and play gambits once your past this level.
I put together a detailed guide on kind of what to expect at each elo level check it out.
From a 500 ELO Beginner to a 2000 ELO Expert
https://www.chess.com/forum/view/chess-players/from-a-500-elo-beginner-to-a-2000-elo-expert
Your list is spot on man the only thing I would change is the amount of time it takes the to reach that Elo like I started playing chess this year in February and it didn’t take me me 6 to 14 months to get to 1100 my current rating on chess.com is an 1110 so I’m still a beginner but I’ve also beaten players rated way higher than me like 1300 n 1200s and I’ve only been playing for 2 months I think this is common for a lot of players in my rating range I think you should add that playing stronger opponents helps you get better faster and it doesn’t take that long to get to that rating when first starting chess the problem with new players is that they don’t know fundamentals and play mindlessly when I first started here on chess.com I dropped down to a 680 in which I stayed around that 680-690 range for about 2 weeks and then I started skyrocketing in points because I asked my self simple questions like what is mr opponents goal in the last move and I followed fundamentals and principles like making sure my pieces were defended and making sure every move I did had meaning once 500-600 elo players understand this it shouldn’t take them any longer than a month to get out of that rating range a great guide that actually helped me a lot was John bartholomew chess fundamentals series where he breakers down core concepts of chess that beginners don’t quite understand yet and Gothamchess winning at chess series also helped this is a great guide I just thought that was the only flaw and gave my input on it

What everyone here said is correct and also I would like to suggest GothamChess. He is a youtuber. He's real name is Levy Rozman. This is Profile on Chess.com: https://www.chess.com/member/gothamchess. He will help you get through. He's also fun. This is his YouTube channel: https://www.youtube.com/channel/UCQHX6ViZmPsWiYSFAyS0a3Q. Here is the video from him that I will suggest to you: https://www.youtube.com/watch?v=X21uL9lbHbw. I hope you get higher than 1200-1300.

I already have around 1,000 games in the 1100-1200 rating..
I see a lot of players with 3k+ and 4k+ games that are stuck at this rating.. I am afraid if i just continue to play i will become like them, stuck more or less in the same rating.
I have not improved much since reaching 1200.
It was easier to win before because people make obvious mistakes like losing a piece.
The problem is at 1250+ people don't make big plunders like losing a hanging piece. And they usually calculate a few moves ahead, even if it's not the best strategically..
But no big blunders and thinking ahead a couple moves makes it really hard to win.
I feel like i will just keep playing and stay stuck at 1250 and just amount 5k games and never improve.
Any suggestions on how to progress from here?
You play blitz and bullet on chess.com that is the problem. Has to be the toughtest place to play as many can play 50-100 games easy without getting tired at all.
One word PRACTICE! Spend 20-30 minutes playing a game or reviewing a GM game. Learn how to play the End Game better. Mating patterns would help for sure. Review your games you lost. What your opponents strategy in the game ..... will it work on somebody else? That alone should bring you to 1350 depending on how much time you put into it.
Well you hit it on the nose. Quality over crap. Anybody can take advantage of error by an opponent. Learn how to create a weakness in their area of the board. Learn how to open up diagonals and files that favor you and not your opponent. Try to keep them closed if your opponent tries this. If they have no path to march their army then how are they going to threaten your king.
Today i play a 50 move game as a 1213 and there were 5 blunders . So is normal or am i bad as a 1200
When you guys say that 1200s don't blunder a lot or make obvious mistakes, I STRONGLY disagree.
If a 1200 plays a stronger opponent (maybe 1800+), he will most likely blunder and lose the game. The problem is that 1200 players DON'T SEE each other's mistakes.
So I would say that 1200s still make obvious tactical errors, but the reason you may have trouble improving from 1200 is that you don't see why such a move was a tactical problem.
I SUGGEST:
analyze the games. See why the opponent blundered and how you could have won. This will help you take advantage of the mistake in a similar position in another game.
You might be surprised how many people have the same common errors. Solving puzzles helps with pattern recognition so that you can see errors in games and know what the winning plan is. Improving tactics will help you supersede the 1200 barrier.
I am 2350. At my level, people don't make such obvious errors, but they still blunder or hang pieces. The goal then is to find how to take advantage of the mistake even if it is a complicated 4+ move winning line. I would say that at blitz, people under 2200 could lose games because of blunders even if the opponent misses the winning line.
At rapid or classical, people 2200+ are the ones who don't make tactical errors but might lose because of positional play.
I already have around 1,000 games in the 1100-1200 rating..
I see a lot of players with 3k+ and 4k+ games that are stuck at this rating.. I am afraid if i just continue to play i will become like them, stuck more or less in the same rating.
I have not improved much since reaching 1200.
It was easier to win before because people make obvious mistakes like losing a piece.
The problem is at 1250+ people don't make big plunders like losing a hanging piece. And they usually calculate a few moves ahead, even if it's not the best strategically..
But no big blunders and thinking ahead a couple moves makes it really hard to win.
I feel like i will just keep playing and stay stuck at 1250 and just amount 5k games and never improve.
Any suggestions on how to progress from here?