This is your first race? Here's what you do: poop before you leave the house, get to the race at least an hour and a half beforehand, register, ride the course a couple times and pick a line through the mud pits, pee at least twice before you race, and HAVE FUN. Bottom line, it's going to be hard, it's going to be exhausting, but you're going to enjoy yourself. Don't worry about the ritual, just go out there and do it.