You're really just missing out on the introduction of some of the characters. Really just Nathan, Sully, and Elena. There are also some nods at the first game, but that's really nothing.

Yeah, the first game has very little in common with the second. You're not missing a thing. Enjoy it though, it's one great story.

If you can get the first one for cheap though you may want to give it a shot since it's a good game anyway. Since you've played the second one already you probably won't enjoy it as mcuh though since they've made some massive improvements for the second one.

I hear the combat has greatly improved int Uncharted 2 so it might be a little hard to go back to Uncharted: Drakes fortune after that but, story wise no you won't be missing much its just that if you did its like meeting up with old friends again when you play part 2.

Thats cool. Yeah I will pick up the first game once I finish this one up. So far its amazing one of the best single player games I've played in a long time, to bad work is getting in the way...

Don't bother playing Uncharted after getting through Uncharted 2. It would be a step back in every possible way.
 
I played through Uncharted last week and thought it was a bit of a turd on the gameplay front.

I just replayed Uncharted and i still found it enjoyable, im playing 2 now and its really a big upgrade, i think i can still enjoy the first one (il try to get platinum later).

you might be confused about who the chick is.

Uncharted 2 is great in that area as it's not a direct sequel for the first game. You'll just basically get a better understanding of the nature of the relationship between Drake and Elena and of Drake's close friendship with Sully, they are like the modern day Butch Cassidy and the Sundance Kid. 

I thought I read that you get bonus cash if you finished the first one for multiplayer. But story-wise, I guess you miss out on some minor stuff really.