I'm no expert for sure, but being ahead in piece count I wouldn't get my king involved in the fight. The bishop on g8 wants to though.
How to better coordinate my pieces
From the starting position you gave black has a very simple plan. Bc3-b4 (preventing any b pawn breaks), and then Nd4 and Bc2, which will either win the b pawn or give up two pieces for a rook (if white can even defend that much), and just be up a piece.
With only two pieces for a rook the position should still be winning, but the king will probably need to be used too.
I like Bc3 more, you are going to win the b pawn anyways, why not make sure that white cannot push his pawns.
But yes, the knight should go to d4.
I like Bc3 more, you are going to win the b pawn anyways, why not make sure that white cannot push his pawns.
But yes, the knight should go to d4.
Because white pawns are not a problem and you must win the game.
How can i improve the position?
Knight on d4 is placed in a perfect square.
After this move white will lose the pawn very quickly.
When you will take the pawn on b3, a3/c3 pawns will become a simple target.
If you will take the a3/c3 you will have 3 passed pawns.
Bishop on c3 is useless and you shouldn't block the position when you are two pieces up. The position must be dynamic.
Bishop on f6 is more active.
Two bishop near are very strong (after Bh7 for example).
White has no counterplay.
1) put your pieces in good active squares. e.g. N on d4, B on h7. Ideally they should be supported by pawns, not by other pieces.
2) identify an easy target, like a weak pawn. In this case b3. Just attack it with everybody.
3) don't trade pawns if you don't get some positional advange in return. The less pawns on the board, the better for the defender.
1) put your pieces in good active squares. e.g. N on d4, B on h7. Ideally they should be supported by pawns, not by other pieces.
2) identify an easy target, like a weak pawn. In this case b3. Just attack it with everybody.
3) don't trade pawns if you don't get some positional advange in return. The less pawns on the board, the better for the defender.
+1 target b3 and all whites queen side pawns fall then promote one of your queenside pawns and it is game over from there

In this game I recently played, I was winning for much of the game. At move 35, I am up thee pieces for a rook and pawn. However, I stuggle to coordinate my pieces and convert the win. Could you give some tips on how to play these sorts of positions? Thanks!