I play for 9 months and i have 400 elo

Stop playing blitz and bullet, play 15|10 rapid instead. Use all your time.
Always check your intended move is no blunder before you play it.
Whenever you lose a game, stop playing and analyse it first so as to learn from your mistakes.

your opponent will usually have a reason for the move they played, most of the time for attacking a piece

To most of my students, I give this advice (and it's almost all they need):
The biggest reason people struggle in lower-level chess is because of blunders. They make them in almost every game.
A mistake can instantly put you in a bad position, no matter how well you played earlier: if you had great opening knowledge, great positional skills, great endgame skills, whatever; a single mistake can change everything (you lose a piece or get checkmated).
So, how do you avoid blunders? Follow these two simple steps:
1. After your opponent moves, think if it's dangerous. Ask yourself, “What’s his idea?”
2. Before you make your move, think if it's safe. Ask yourself, “What attacking replies can he play?”
If you feel like getting to levels like 1600, 1800, or 2000 in chess is super hard, let's look at it in a different way. Those players you're facing make blunders in nearly every game they play. Beating them isn't so tough if you stop making big mistakes and start using their slip-ups to your advantage.
Again, it does not require you to become a chess nerd or spend all your time on chess. Just doing this one thing can boost your rating by a few hundred points right away.
Lastly, while avoiding blunders is crucial, I also share a few basic principles with my students. These principles help them figure out what to do in each part of the game - the opening, the middlegame, and the endgame. Understanding these simple principles is like having a map for your moves. When you use this knowledge along with being careful about blunders, you're not just getting better at defending. You're also learning a well-rounded approach to chess. Keep in mind, chess is not just about not making mistakes; it's about making smart and planned moves to outsmart your opponent.
To most of my students, I give this advice (and it's almost all they need):
The biggest reason people struggle in lower-level chess is because of blunders. They make them in almost every game.
A mistake can instantly put you in a bad position, no matter how well you played earlier: if you had great opening knowledge, great positional skills, great endgame skills, whatever; a single mistake can change everything (you lose a piece or get checkmated).
So, how do you avoid blunders? Follow these two simple steps:
1. After your opponent moves, think if it's dangerous. Ask yourself, “What’s his idea?”
2. Before you make your move, think if it's safe. Ask yourself, “What attacking replies can he play?”
If you feel like getting to levels like 1600, 1800, or 2000 in chess is super hard, let's look at it in a different way. Those players you're facing make blunders in nearly every game they play. Beating them isn't so tough if you stop making big mistakes and start using their slip-ups to your advantage.
Again, it does not require you to become a chess nerd or spend all your time on chess. Just doing this one thing can boost your rating by a few hundred points right away.
Lastly, while avoiding blunders is crucial, I also share a few basic principles with my students. These principles help them figure out what to do in each part of the game - the opening, the middlegame, and the endgame. Understanding these simple principles is like having a map for your moves. When you use this knowledge along with being careful about blunders, you're not just getting better at defending. You're also learning a well-rounded approach to chess. Keep in mind, chess is not just about not making mistakes; it's about making smart and planned moves to outsmart your opponent.
Good sir no offense I have seen you post this thing dozens of times in different threads are you a bot? I'm not trying to be mean or anything.