Welcome, its nice to see that you're not only interested, but also taking initiative to get more information and reaching out there any way you can - Commendable for a 14 year old!

It depends on what you want to do really.

Do you want to repair car? Do you want to tune them? Do you want to work for BMW in the R&D department? There are an incredible number of ways you can contribute.

Since you have quite some time before you have to decide on your major in college, for now I recommend that you just soak it all in and find an area you're interested in. In high school, try to get as much experience as you can and maybe work part time at a shop or something like that. You wont know if something is really for you until you try it.

Good luck! You're off to a great start.