It's basically you just say you're having a wedding if you want one, and if people want, they can come. A contract is not needed, there's no special place for it, it's just pretty much a role play thing.
There is no plugin, however many users decide to get married. I'd be glad to talk to somebody, and arrange a wedding if you'd like
Well the problem is at my house there is only one computer so I play while by boyfriend is at work and he plays when he is at home.
it's an application for phones/tablets that let's you be in game for minecraft, without playing. But your character is there, and you can chat!