There will normally be a compulsory matriculation formal, and possibly also a graduation one. Most places will also require gowns for those, though lots of people borrow them just for that.
Formals are fun and you'll certainly want to go to some before you decide you don't like them. Some people seem to think they're nothing but an excuse to get paralytic though, pennying is ubiquitous.
I like proper silver service formals, it isn't the same when you have to serve yourself. There tends to be all the proper etiquette crap to deal with but it's just a load of easy to follow rules, that people tend to judge you by. A lot of people don't even try to do it 'right', so you're unlikely to be frowned upon if you don't eat your soup in the 'correct' manner. I never eat the bread 'properly' as I think that's just silly, so I rip it open .
You'll enjoy formals once you've sampled them though, I'm sure.
You make it sound nice! Do the tutors get drunk?