Horrible pay, long hours, mean customers, crappy bosses.
It's not a bad job to have if you're really into it, but you get paid precisely crap unless you have your own shop. Median income is around $11/hr almost no matter where you live (you'll probably make $7-$8/hr starting out, even if you were to graduate from MMI or something like that) and you're lucky if ever get near $20/hr, so don't plan on moving out of your parent's house for a very long time or plan on having a family or a life.
I hate to paint a bad picture of it, but that's exactly what you are looking at. Good luck!