Actually, starting at the end is better, since a player must know how to launch checkmates in endgames.
I am serious about learning chess. Where should I start?

I recommend looking up NM Robert Ramirez, he has a free series of about 130 videos, each about 20 minutes long, that will get you up to competent player in short order.

Learning common mate patterns and how to checkmate with Queen and King without stalemate and Rook and King without stalemate would be a nice start too. Learning the "staircase" pattern with Rook and Queen is essential , can be two rooks too sometimes. Since the goal of chess is checkmating the opponent you can't go wrong with getting good at checkmates. Try checkmate in 1 problems first until those get really easy for you, then even if it takes you two moves at least you know what you are looking for, if you remember basic mate patterns it'll be much easier for you.
Then solve a bunch of tactic problems, solve a 1000 problems, and then you'll be way better than now. You can solve them on lichess or chesscom but I think chesscom has a limit if you don't have a paid membership whereas lichess is free xD
If you start to feel a bit comfortable with tactics then your problem solving skills will help you become more analytical and you might be able to analyze your own games, you'll want to spend time analyzing your games if you're serious about improvement.
Just try to avoid making the same mistakes every game, if you notice you are blundering pieces then you need to figure out why you blundered the piece, did you not see they could capture you with a bishop, so you would get used to the pattern of blundering a piece because of the frustration eventually, but if you spend time analyzing the game after it's less likely you will blunder the same way because you learned that it's a blunder and understand why it happened.

Also playing slow games with more time can be very useful for improvement, slow serious games where you try to think more help a lot. But I'd do this more after you have a 1000 tactics under your belt so you're already at a comfortable position mentally with chess and don't get too tired from chess.

1)start with hyperbullet.
2)then retire at the rating you’re happy with.
3)switch to play blitz
4)then retire at the blitz rating you’re happy with.
5)switch to play rapid.

Welcome to the world of chess!
Play a few games here online first.
There are a huge number of decent chess books out there, many specialise in a particular area of the game such as opening/middlegame/endgame. I recommend either or both of these general books:
The Mammoth Book of Chess by Graham Burgess
A Guide To Chess Improvement by Dan Heisman
These books are suitable for beginner to intermediate level players (up to about 1900). You will benefit from reading either of them a second time after you are a bit more experienced.
Practice doing chess puzzles. This site has the rated puzzles and also puzzle rush both of them will improve your tactical skills.
It is good to support this site via a premium membership and you get the lessons/analysis/puzzles etc.
There are also many, many chess YouTube channels from many strong players. Gotham Chess is the most popular. Some others are NM Robert Ramirez, Kingcrusher, Hanging Pawns, Chess Factor, Chess Dojo, Agadmator, Daniel Naroditsky, Saint Louis Chess Club, Big Mio, and Daniel King Power Play.
For becoming a good tournament player, it is useful to play slower time controls. 30 minutes or more.
1)start with hyperbullet.
2)then retire at the rating you’re happy with.
3)switch to play blitz
4)then retire at the blitz rating you’re happy with.
5)switch to play rapid.
But he might not get past the hurdle of playing ten moves in a game.
Or he might even lose on time on the second move.

Start by playing ONLY 30+0 and longer, sometimes shorter games but only to learn how to move the pieces and pick up on threats a bit faster... If you have the opportunity, play OTB as soon as you are confident (semi) in your skills, it's. a wonderful learning experience.
Start by playing ONLY 30+0 and longer, sometimes shorter games but only to learn how to move the pieces and pick up on threats a bit faster... If you have the opportunity, play OTB as soon as you are confident (semi) in your skills, it's. a wonderful learning experience.
Unfortunately, this is somewhat hampered by the global COVID-19 situation (the nationwide protocols vary among different countries).

1)start with hyperbullet.
2)then retire at the rating you’re happy with.
3)switch to play blitz
4)then retire at the blitz rating you’re happy with.
5)switch to play rapid.
But he might not get past the hurdle of playing ten moves in a game.
Or he might even lose on time on the second move.
He will for sure improve after playing thousands games👌
Hi I started playing chess for fun with my friends some time ago and I think I like it quite a lot. I want to learn how to play for real. Where should I start? Do you have any books/tutorials recommendations https://19216801.onl/ ? I would like to learn from the ground up to become a good player (good enough to be competitive in tournaments).