Someone analyze my game and give me some tips plz

I'm not a master at explaining. But I would recommend you to watch YT channel Chess Vibes to get better at chess. This channel really helped me to realize the sense of the game and the sense behind each move.

There’s a few things I could comment on but the main thing that stood out to me was the …f5 move as that’s drastically weakening; sure yes you can sometimes do that kind of thing but unless you’re sure you’re going to be whipping up a really serious attack to compensate for the weaknesses created (in other words being sure you can go …f4 next with mayhem even if it’s not fully sound) then you don’t really want to go there.

other than that I didn’t really believe the plan of going …Bc7 and …Qd6, pawn structure is a reversed Carlsbad QGD so some sort of minority attack with …b5 suggests itself (maybe instead of …Bc7) combined with staying solid on the kingside.

that being said you’re far from being a beginner / weak player so I believe you’re capable of being able to draw these conclusions yourself

James is absolutely right! In this variation you have (almost) nothing to do on the kingside, you have to do the classic minority attack: b5, a5, b4 etc., weakening the pawns on the queenside with comfortable positional play. You hade a very nice position, your opponent didn't have any threats on the kingside. Never mind, you can learn much more from loosing than from winning