Many places that sell earrings also do the piercings. Be careful though. Take your own judgement, do they look and act professional? And at most it will sting. Not as bad as you think. This is coming from a guy who has his ear pierced multiple times.
Cartridge. It doesn't hurt as bad as you think it's going too! It just is a little sore if you sleep on it. Im 14 and got mine done last summer and loved it! It's cute and not to expensive if you go to the right place.