If you can find another way to make money, I would suggest looking into that first. It's not a bad job, but there are better out there. Plus, the money used to be better, from what I'm told. UTI is a one year school. 5 days a week, 6 hours a day. You learn the basics of cars there (engine, trans, suspension, brakes, diffs, electrical, etc). If you do well enough in school, you can go to one of the manufacturer specific courses paid for by the dealer you will end up working for (many courses; audi, vw, bmw, porsche, ford, volvo, jaguar, and a few others). Or if you don't do well enough to get into those, there are a few that you can pay for yourself.
I wish I would have gone into the BMW program, but I didn't. I ended up moving to be closer to family, and starting out at a GM dealership. When I moved back to Cali (Palm Springs), I walked in the door and was hired on the spot because of my schooling and experience. When I was ready to move closer to the beach, I again walked into a dealership and got hired on the spot.
It's really hard to give an average starting pay. The way we get paid is called flat rate. If a certain job pays 1.0 hour, then no matter how long it takes you, you get paid 1.0 hour. If you take 3 hours to do it, you get paid 1.0 hour. If it takes you 5 minutes to do it, you get paid 1.0 hour. And the pay rate greatly varies by dealer. I've heard of master techs making anywhere from $20-$35 per hour. Just depends on the actual dealer.