Don't go into a piercing parlor expecting that you'll be done once you walk out the door. Piercings can take weeks to heal, and require a fair amount of aftercare before everything's back to normal. Your parlor should provide you with an aftercare sheet before you leave.
While piercings are by no means as permanent as tattoos, they're costly, they hurt, and there's always a chance of infection and illness. That being the case, be absolutely sure you're clearheaded before you enter a piercing parlor and arrange for a piercing.