Ultimately, the decision is up to you. Before you make your decision, though, do some research on it. Anytime you get a piercing in your mouth, it is going to damage the enamel on your teeth. The metal jewelry will chip away at it and will cost you thousands of dollars in dental work later. For me, that would make it not worth it. But you have to decide for yourself.
And as for the "employers don't want pierced or tatted up employees" talk... It depends on what field you are going into. Also, it is possible to have multiple tattoos that no one can see. I have three and my employer has no idea. No one would guess it by looking at me, either. But you can have tattoos and be successful. I know surgeons and lawyers who have plenty of tattoos. Just saying.
You mean you'll get your parents to pay for caps for you or you have the money to waste on getting a ridiculous amount of dental work done?
I have a couple visible tattoos and was hired by a government agency with them. Actually ill be getting another one soon I say do you whatever that is. If you're happy then I'm happy for you. It's your decision. I wouldn't pierce my lip but I don't knock those that do.