I heartily agree with everyone who’s suggested that you get this done professionally. I live next-door to a tattoo/piercing shop, so I would say I’m pretty knowledgeable about piercings in general.
Depending on the area in which you live, piercings can cost anywhere from $30–50 each (including jewelry). That is if you get it done by a professional studio and not some ridiculously broken place like Piercing Pagoda; these people are hardly qualified professionals and most only watch a lame thirty-minute video for “training”. You most definitely don’t want to put any of your body parts in their hands. Real piercing studios are ten times more sterile and know exactly what they’re doing. That said…any piercing in your lip is bound to scar, so if you screw it up or it gets infected and you have to take it out, you’ll have to live with it forever. The real deal studios know all about the anatomy of these things and about the right kind of jewelry types to suit the piercing and the person. I once saw an eighteen-year-old kid come into the studio with his mother because his labret had grown into the inside of his lip. They had to dig it out with a scalpel and I can’t describe for you how disturbing it was to watch this kid…or the blood…or the screams.
So yeah…save your money and get this done at a reputable studio, preferably with your parents’ permission.