I just sent my kid off to University of Texas on a track scholarship, so maybe I can help a little bit knowing what "we" did over the teenage years to guide him towards success.
First, of course, is to know in what events you most want to compete. Are you a sprinter (probably not as your specs indicate you are of slender build) middle, or longer distance? What other sports are you involved in, and what do you excel at right now?
One thing I can tell you right now is that at your age, a commitment to training can have significant impact on your success...my kid had tremendous natural ability (did not come from me) but when he would get lazy on the training and conditioning, it showed. Also, he exceled at other sports as well, but he has glass ankles, and was getting injured all the time, mostly in basketball. Then training again suffers. Keep yourself healthy.
Right off the top I would think you need to run, run, run. The day my kid hit Austin, the coach has them running for an hour solid, twice a day (he is mainly 800-1000meter runner) and no time trials until just 2 weeks ago. His times were absolutely amazing. Your 1 mile runs don't do that much...at best you are running somewhere around 6-8 minutes I assume. Try running for 20 minutes, at a brisk pace, and see where you're at. If you can still talk and stand up, bump it up to 25 minutes, etc. Don't worry about the distance yet, you need to build up some endurance and get to know the signals your body is giving you, then you can apply that knowledge when it comes time to timed laps, etc and knowing how to pace for the race.
As for advice on resistance training, I probably will shy away from this as there are true experts here, and more importantly, it would be irresponsible of me to suggest things like this to a minor...try getting in touch with your high school strength coach to see if you have an opportunity to get some supervised training.
Don't get involved with any silly supplements, either. Eat well, and stay away from the junk. That's pretty simple.
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