Hopefully no-one's annoyed by me and my questions yet

Round 1, with White:
I was quite surprised by 20. ... Bc5. Is 20. ... Bc8 21.Nxc4 Rxa7 not better, since material is even? 23. Nf3 was silly. I thought, "that knight is undefended, so I should move it" and didn't see that Nd2 was clearly better, since it moved the piece so that it was defended, but also attacked the rook. 29. Rac1. Wtf? Again, I should have attacked the rook with Bd2 perhaps (though I don't know where I'd have gone from there). I thought I'd played reasonably well, but now I'm not so sure..
Round 2, with Black:
I have to say that this game felt very cramped for me. I couldn't work out how to put my pieces on good squares and it felt like I had no control over the game. I also wanted to get rid of my opponent's dark squared bishop much earlier, though I couldn't work out how to do that either

My opponent said that I'd played quite a tough game and played close to his strength (116). I'm not sure that's accurate. If he'd seen a bigger sample of my games, he wouldn't have been so complimentary

This game seems quite complicated and I can't pinpoint exactly where I went wrong. Maybe it was just that c pawn; I dunno. In case it's not obvious, I'd given up hope by move 42, so I took the knight and then resigned.
Were there any differences in my play in the two games (whether performance, style, or otherwise)? Should I be starting to learn openings properly now? I think I'll be trying to play more slow congresses (finances permitting, though I'm playing one Weekend Classic this December), as well as league chess. In both cases, I'm probably going to face opponents below 140 (like at this event) or below 120. As such, I think it would probably be wise to learn some openings properly, since otherwise, my opponents will be more prepared.
Thanks!