How to win over your crush that you had a bad first impression on...?

Let me start of by saying, this boy is super hot! but he is kinda dorky at the same time...so he's not usually my type, but anywho--->I've been liking this boy sense the middle of my freshman year, I'm now just starting sopre year about a week ago...He has a girlfriend, but they have only been together a few weeks, so it's nothing too serious yet. I know he watches me when i walk into geometry cl, and it's not just a staring type of watch, it's an interested type of watch, and he always smiles at me, so my friends tell me they think he likes me. (: XCEPT we like, never talk...So Me and my friends ended up chilling out with him and his friends at one of our HS football games. [including his gf] he was laughing and it sounded funny&dorky, i didnt mean to, but my friends are always draggin me into trouble, lol, and long story short, i'm pretty sure he over heard me and my friends kinda making fun of him!! [most of my friends are boys, so they were gettin pretty rowdie...lol] and my best friend reggie said he was giving me nasty looks after that...so now i KNOW i screwed up. lol.....what can i do, besides apologize??? I plan on apologizing but i don't think that would be enough....yeah, i know, i'm stupid...