Odds of Getting In
You'll have to crack a lot of book spines if you want to crack human spines for a living. There are only seventeen chiropractic schools in the U.S., which combine to graduate roughly 200 new chiropractors every year. It's not as competitive as the pro golf world, but it's not a breeze, either. You'll need to do well in high school, get into a decent college, and research chiropractic schools to figure out which one will be the best fit for you. Once you get into your dream chiropractic school, you'll have to keep your nose in those books if you want to succeed.
Still though, your odds aren't bad. Once you're licensed, finding a job should be relatively easy. We can't think of any place on Earth that doesn't have people with back pain.