Hi, i was wondering if anybody could take a look at this game for me.

 

I am not sure if 21.f4 is any good.  Why not 21.Nxd5 and exchange knights?

 

The endgame is won for Black once the Queens come off the board.  Black has 4 pawns (3 passed pawns) and White has 3 pawns, but two of them are doubled pawns on the rook file. 

 

37...Rg8 gave away a pawn for Black.  Black can play 37...Rc8 to back the passed pawn or 37...Rb2+ and 38...f5, or just 37...f5.

 

After 40.Rd6, Black wins with 40...c2.  If White playes 41.Rd8+ and 42.Rc8, Black simply plays Nc4 and the pawn Queens. 

It would be nice to see some commentaries for amateurs like myself.

My dad usually always wins, and I was pleased that I finally beat him after all these years 

No comment except very well played