I suggest being involved in music in high school so that you can learn to read music well. A lot of rappers I know, can't read music, do they are difficult to work with in a studio. Try choir if you are not playing an instrument in band or orchestra. Also, theatre is a great place to get stage experience and work on your diction. Rappers with unclear diction aren't as good as those you can really understand!
Keep putting your music out there so that people will here it. Look for places to perform...probably for free when you are first doing live performances. Some shopping venues have summer concert series, and some restaurants have musicians perform certain nights each week, or your school might have a time in the cafeteria or library each week when students share their talents. If they don't, get it started!! Kind of minnie concerts. My high school called it Friday Unplugged!
Do you have clean language in your raps? If not, please do so right now at your age. Many of the venues where you can perform now will probably have audience members under 18 years of age. So be aware of your audience.
Study and listen to all types of music, even if you don't like it. It will help you be better at your favorite style of music! Consider studying in college. There are a few schools who have pop music degrees, but for sure get at least a liberal arts degree so that you are well-rounded. The more knowledge you have, the better your music will be.
Keep studying, working hard and performing and opportunities will arise. You might be famous one day, but eve if you are not, you will always have opportunities to share your talent and affect others in a positive way. Many musicians have careers in fields other than music, to make money to support themselves, and that's okay. You keep singing though, no matter what! And if you do rise in fame and end up on the Grammys one day, give me a shout out!!