Ok, what makes you think you can't do things once you are older!?! I had my first tattoo at 40 ..... about the same time I was lecturing about piercings.
As for any facial piercing - the odds are you will live to regret it. Sorry, but except for a few "freaks" I know that still wear theirs (in their late 30s, along with full body tattooing) everyone ends up regratting the scar (or worse) later.
Lip piercings are easy to do, easy to clean, but a real job to take care of till they heal. Its too near that germ factory known as your mouth to ignore a serious hygiene regime. Get lazy and you will have a bigger problem. At least its easier than your tongue. And be ready to face constant criticism from all but your devoted peers. You can't hide it from anyone, so you will look like just another teenager that couldn't resist the fad.
BTW, not everyone likes kissing a metal ring.
Sorry to be harsh, but you need to be ready for it if you are going to pierce any part of your face.
But don't get me started on belly button rings.
