Go, have fun. Since there is a group of people you want to see, you'll be fine. If worse comes to worst, you can always bag it, and go somewhere else.
As as many have mentioned, time has a way of changing everyone. Sure, you'll probably have a few people that will have their trophy spouse, or will try to impress you with their career or status, but so what? If they feel like they have to do that, that's their insecurity.
Don't worry about the fact that you are just going to college and etc. pick out a couple of good stories from your 10 year journey. I didn't go to college right away, and a lot of people said they wish they hadn't gone right out of HS because they didn't know what they wanted.
Let us know how it goes.