Back in the day they usually had a EM/sage/counselor help out with
UO weddings, so you can start from there.
However, a lot of stuff like this is mostly player run, so you might have to try doing it on your own, too. You may be able to get some help from a GM, but more than likely they won't. Like I said, they helped a long time ago, when they had nothing better to do, but now not so much.