Go work in a car shop right now. Start by sweeping the floors or straightening out the tools or whatever the shop foreman or owner needs. You'll learn if you really like it. Just as important, if you express an interest in owning your own shop one day and you work hard, there are many owners who will eventually give you tips on how to open your own shop. In this way, you'll get your own mentor --your own coach from someone who is in the industry! The key is: you're excited to be there and you see what you want. No hemming and hawing or being too cool to show interest. Adults are reluctant to give advice to kids who don't express an interest and who don't work hard.