Congratulations on the right to get married! Now it's time to get married right. Obviously you need somebody who's been there before to guide you through the process (a "straighty"), and so you've come to the right place. I'm a traditionalist when it comes to marriage, but I've done my best to update my advice wherever possible. So hang onto your garters, gays, lesbians, and those other letters—it's going to be a bumpy ride!
Marriage, as you already know, is a divine contract between two landholding parents who want to join their farms. They do this by forcing their children—ideally first cousins—to have sex and file taxes jointly forever. God originally handed down the sacrament in the Book of Genesis, though he later clarified the rules of marriage during the Council of Trent in 1563, admitting, "Some of My original writing on the subject was unnecessarily vague. Hope this helps. TTFN!—God"
If your parents aren't lucky enough to own arable land, you're going to have a harder time finding a soul mate. The only chance you have is to let the really gossipy neighbor know you're on the market, and with any luck, you'll soon be inundated with aged widowers inviting you to supper. Lock them in with your witty conversation while your parents awkwardly watch. Glance at each other shyly. Brag about your dad's milk cow. Two or three of these gatherings and you know you've found a partner for life.
Once your life-mate and father have come to a mutually agreeable bounty, it's time to have a ceremony. A wedding is a joyous celebration of a family's ostentatiousness, as well as a chance for a priest to verify that you're still a virgin through a series of invasive and scientifically rigorous tests. During the wedding, you should wear something old (to remind you of the past), something new (representing good fortune), something borrowed (signaling friendship), and something blue (because it rhymes with "new").
A whole world of fun awaits you after the wedding ceremony! You've been saving yourself for these last 14ish years, and now it's finally time to have sex (unless you haven't waited, in which case, please jump ahead to "Section 243: Rotting in Hell Forever"). In a straight marriage, both God and Man's Law agree that only one of the partners is entitled to pleasure and fulfillment. Since you're both the same gender... um... I don't know. Maybe roshambo for it?
Next, have (or in your case, borrow) a lot of kids. Like, a LOT of kids.
Don't despair if your traditional marriage isn't working. Even though the bond of holy matrimony lasts forever in the eyes of God and the law, it's also fully reversible! Before you jump into beheading your husband/wife, remember you can get divorced now with an act of parliament if you have enough money! Again, this gets a little muddled by intra-gender marriages so I can only assume two men can divorce each other for any reason, but two women can't get divorced at all.
If you follow these simple steps, you'll soon be enjoying all of the joy married life can afford. But tread carefully! Make sure you treat marriage as respectfully as we straightys have for the last few thousand years.