There's no way you can have a job that will pay for tuition (not legal anyway ). Med schools have work study programs where you can work and study at the same time, such as working the main desk at the school library. It will help pay for some of your groceries, but that's about it.
Unless you're rich, plan on going very heavily into debt.
Of the med students I've encountered, I haven't run into one working more than 10 hours a week. That certainly won't cover your tuition! I wouldn't recommend working unless you are able to study on the job.