I'm going to post my last 2 games against erik here. The first one I play white with a king's Indian defense. The second one I play with black "something" against King's Gambit (declined).

The first game is, so far, my best game ever. The second one is my fastest loss.

I would like a word of advice on how can improve my game against unknown openings, regardless of the obvious which is, I need to study more opening theory.

Here they go:

Amateurs (you and me both!) are quick to blame opening theory for our losses, but your first mistake (7...Bh5) was tactical.  By the way, 7...Bxf3 isn't so bad. To eliminate your bishop, White had to waste a tempo on h3 and create a kingside weakness (where he's castled). He's also traded off a piece, which favors Black more than White. Finally, after 8.Qxf3 Nd4! is annoying. In fact, I might slightly prefer Black's position.

11.Bxf7!? Kxf7 12.Ng5+ Qxh5+ - Erik's dangerous when he smells blood in the water... I'm glad it wasn't me on the receiving end.

8...exf4 "So I choose how to lose it" - Often in these sorts of positions Nxg4 hxg4 Bxg4 is a good idea. In this case, it might not work because of his imminent attack on f7, but it's worth considering. Two pawns for a piece, especially the two pawns protecting his king, are almost but not quite compensation.

13.Qxh5 - "I can't stop mate" - He's a piece up... but where is mate?? I don't see it. 13...Kf8 14.Qxg5 and now what?

Personally I don't like the 6.Be7 move with the c pawn is behind your c6 knight the queens movement/influence on the game is to limited.  I would of looked to fianchetto the bishop looking to come to e5 if he played fxe5 to open the f-file for his rook.  Also with the queen potentially coming to the f3 doubling up with the rook at f1, probably followed by an attack on your kingside defenders with moves like Nd5 and Bg5 (later on of course).  I would of looked to castle queenside as early as possible.