The halls I can imagine are not for everyone's taste, it is not for me I must say. I do like meeting new people and have good talks and socialize, but I am not that keen on drinking or have constantly had to try and "fit" in.. Hard to explain, but I like meeting other people but I don't like it when I kind of have to feel forced to fit in.. I hope that makes sentence.. gulp..
I think uni in general, is what every person wants it to be.. If is drinking to the early morning, there is a group for that, if it's meeting new people there plenty, if it's to study and otherwise have some good conversations and enjoy the studies there is a group for that.. I really think that uni will be what you want it to be really.. And yes sometimes we need to get a little out of our shell and take a leap to enjoy life, as long as it does not interfere what we believe in as morals and guidelines as a person..
If I may be a little blunt, but I think a gap year is healthy, it can mature a person and be an eye-opener i think..
I really don't think you should worry so much, I think it will be a great experience with lots of new friendships and enjoyment to look forward too.