This depends on your state's specific labor laws. If you are in a right to work state, you can contract and be scheduled for any hours. However, in California there are maximum daily and weekly limits.
Minors cannot work more than 40 hours combined school and work. Other than that there is no limit to the hours you can work, you do have rights to breaks.
Maximum hours are whatever you agreed to, but you are not allowed to work seven straight days or any 24 hour days. If you agree to 5 - 16 hour shifts, then you work what you agreed to.