What are the rules about gay proposals/weddings?

So I'm not anywhere close to getting married, but I'm kind of still in the dark about how gay proposals and weddings work.What's the situation for rings? Are wedding bands appropriate for engagement rings? If yes, are wedding bands for the wedding any different? There's no guy and girl in the relationship, so who generally proposes? Are there bridesmaids and groomsmen at weddings, or just two sets of bridesmaids/groomsmen?Forgive my ignorance or potential rudeness, I'm from a very old-fashioned family, so I don't have anyone to look to. Thanks!