Its in the first week that you get to meet everyone and bond with a particular group of people.
Even if you THINK you'll hate it, you'll have fun meeting new people. Its harder to break the ice later on in term. First impressions can stick, so make sure your not 'the boring guy who doesn't go out'.
A wise head on young shoulders!
That first week really is important, everyone's in the same boat and receptive to making new friends. After that, the little groups form and the shutters come down. You'll still make friends, but it'll be much harder work. OK, you're not into the R&B/gangsta shite but even if you're going to be an outsider, now's the time to find the other outsiders!!
I was (am) very lacking in self-confidence; I ducked out of the freshers week thing and after that it took a really long time to make friends (or maybe I just smelled funny :? ). This was 25 years ago and I still bitterly regret it. Yeah, I worked hard and got a good degree, but I honestly believe the main point of University is to get away from home, meet people, maybe make some mistakes, learn from them and "grow up" a little.
Maybe you're a confident sort and I'm sure you won't have the same problems I did, but you have 3 or 4 years ahead of you to meet hundreds of people your own age, from different places and backgrounds and with a huge variety of interests. You'll never get such an opportunity again, so please don't get off to a bad start.
Sorry for making your thread all serious... :(