Queen's gambit
d4 opening recommendations for black?
KID theory is extremely complicated but worthwhile to learn-brings in good results for me lots of times

Okay. When I was new to chess, I struggled with defending against d4. So I started my strategy.
I mostly take the pawn
But I also play the semi-slav or slav
I prefer the semi-slav when I want to trade queens and go to the endgames. Mostly, that is how I win against the 2000-rated players. But, with the semi-slav, you have to develop your pieces to the side your opponent's king has castled. Then, with your active pieces, you should not trade pieces and launch a deadly attack on your opponent. But, if your opponent doesn't castle, you should develop, push your pawns, attack, and try to capture as many pieces as you can. Try to make reasonable moves.
Here is some practice:
In this position, you got a free pawn. Remember, a pawn is enough to decide the whole game.

QID. Works against the Catalan too. If you don’t wanna get too theoretical you can play the Ba6 line but choose an opening that fits your play style.

Okay. When I was new to chess, I struggled with defending against d4. So I started my strategy.
I mostly take the pawn
But I also play the semi-slav or slav
I prefer the semi-slav when I want to trade queens and go to the endgames. Mostly, that is how I win against the 2000-rated players. But, with the semi-slav, you have to develop your pieces to the side your opponent's king has castled. Then, with your active pieces, you should not trade pieces and launch a deadly attack on your opponent. But, if your opponent doesn't castle, you should develop, push your pawns, attack, and try to capture as many pieces as you can. Try to make reasonable moves.
Here is some practice:
In this position, you got a free pawn. Remember, a pawn is enough to decide the whole game.
The third position is a bit wrong. Instead of Bxc4 just take the free knight or play Bxa7.
i struggle a lot positionally and lately i try to play normal QGD lines but feel stuck during the middlegame or how black is even supposed to proceed. i also play slav and looked at some hikaru youtube videos where i see him playing c5 as like a reverse QG against the london with qb6 and maybe bc5 treating it as a weird opposite french. i just need some help playing against d4 feeling comfortable with using one opening or more, thanks