b5 is not a known opening. It exposes your valuable rook to diagonal assaults while not accomplishing much to pressure the center (e4 d4 e5 d5 are the center) and as you discover, his natural development of the knight attacks this pawn.
nf6 loses the b pawn. defend it with a6 is probably best here.
6) good, he throws away a piece and you grabbed it.
11) remember what I said about that vulnerable rook on move 1? The best you can do here is save the rook with Nc6, which loses the knight instead. Or, if you think you can make it work, lose the rook and exploit the deep knight to somehow find an attack on his king, for example Qf6 would lead to mate if he takes the rook (try to find this mate).
you should castle instead of Ke7. Its better for your defenses.
13) goodness. You are a queen ahead and are winning now.
14) simply taking the piece with your knight is superior.
17) forking his rooks with your knight is superior (Nxf2)
18) watch out: your queen and king are aligned with his rook, this could cost you your queen, get your king away from this setup! Qa2 is a good move, it threatens mate, but costs you your knight and a tempo (forced move is a lost move, in other words, you can't do what you want because he checked you). Move the king to safety first then do Qa2.
23) right idea, but queen check instead of bishop check looks better to me. This frees your rook to assault him on the back rank, or if he does not go back, you win the pawn and can start an attack sequence on a very vulnerable king.
and from here its a pretty easy win for you.
I would say to take 2 things away from this game:
1) learn a few opening ideas. your very first move caused you more problems than just about anything else you did.
2) practice with your knights. You missed a couple of gems with your deeply placed knight.
Tips and errors I made? Make it easy to read please. The last analysis I posted I didn't understand one of the responses. Make it so a beginner can read it.