Where can a 12 year volunteer in the medical field?

Hello there. Im Elizabeth and im 12, turning 13 in august. Its summer time and im off from school and i really want to volunteer in the medical field in my spare time. I want to be a doctor and im very mature for my age. I know a lot about medicine and diseases and i live in Waxhaw, North Carolina. I jut want a chance to make a difference and im to impatient to wait