16. Have fun.
For all this advice--be yourself. Either the relationship won't work out and it ultimately won't matter what these people think of you, or else it will work out and they're going to have to get used to you as you are. So don't put on an act or contort yourself into someone you're not in order to fit in. Be kind and helpful, tolerant and a good sport. But don't feel the need to be a pathological pleaser or put your personality on hold for however many hours or days the celebrations last.