Well, to me, that sounds like you've got the worst part out of the way. I always have to go to these things by myself and end up feeling like I'm tagging along with my couple friends. At least you have someone to dance with, that is if you want to dance.
The folk I know aren't very classy, so the last black tie thing I went to was basically a dance with an excuse to get dressed up. The family who organised it hired a nice venue and had a buffet meal laid out.
Is it a dinner dance? Have you been given any information on the invitation?