What are your advices for 750-800 elo rating?

this is an exercise that I am creating just for your purpose. clear the board and put only one piece on it. move it around till you almost memorize where all the piece has been to. do this with each piece and try to remember it's position on the board at every instant. now remove all the pieces and put only pawns. experiment with different pawn structures. put fewer pawns if that suits you. move it around and try to remember how many squares you control.

now study basic endgames. how to mate with king and queen vs king, king and rook vs king, two bishops verses king(this is important) yu don't need to do knight and bishop versus king that's too hard even some GMs have failed.