What am I doing wrong?
My advice (as a chess coach and 2100+ player):
Learn and apply the most important principles of chess.
Always blunder-check your moves.
Solve tactics in the right way.
Analyze your games.
Study games of strong players.
Learn how to be more psychologically resilient.
Work on your time management skills.
Get a coach if you can.
Improving Your Chess - Resources for Beginners and Beyond.....
https://www.chess.com/blog/RussBell/improving-your-chess-resources-for-beginners-and-beyond
I watched one of your games. Some things I noticed:
- you lack an understanding of positional concepts. For example, multiple times you developed pieces in front of pawns and it was a queens pawn opening. One time your bishop was on f5, it got attacked and you could have withdrawn it to g6, you'd already pushed the g pawn to g5... it would have been behind the g pawn and guarded your king there. Instead you withdrew it to d6 where you blocked in your d7 pawn.
You lack an understanding of space and the importance of controlling the center / playing for a space advantage.
- the second part is just that you made a basic tactical blunder in the game, you moved a bishop to a square where it was guarded once and attacked twice. For this you really just need to work on your tactics.
But for the positional understanding my recommendation would be that you begin learning the queens gambit on a very basic level. Not deep just the first 4-5 moves, know what they are... Go watch some youtube videos introducing you to the opening and learn that. It does not take long and it isn't that difficult, but at least you will get experience taking up space and playing a classical game.
You want to push your pawns - especially your center pawns, you should at least move them to the center and control space with them... if they can't reach the center, at least move them to d6 or e6 or something. And often you want to push your c pawn as well. You don't want backward central pawns still on d7/e7 that block in your pieces.
Generally it's good to be conservative with pushing the pawns in front or your king, too. If you fiancetto it's okay because the bishop will guard your king. But if you aren't going to fiancetto you should be very careful before exposing your king. This is why usually people push the c pawn, but not so much the f pawn.