Matthew recommends the following next steps:
Making it to the NBA will be a result of you continuing this same work and dedication at the collegiate level. You will also need to be highly productive at that level as well to get noticed by NBA scouts.
You should join an AAU team it helps with exposure to coaches. Also going to recruit camps on the summer. When you go to tournaments on your AAU team you should email the coaches times and places where you will be playing. You usually will get a list of what schools are in attendance
When you are not involved with the stuff I mentioned above. Work on your shooting, ball handling and rebounding skills as well as footwork.
As far as school, talk to your guidance counselor, make sure you take the SAT/ACT and meet the NCAA clearing house requirements to assure you have the grades and classes to go D1.
NBA prospects work extremely hard and many people start to realize who prospects are in their senior year of high school and even throughout college. It is extremely hard to achieve this goal, a small percentage of athletes are able to achieve this goal. Same as becoming a student athlete in college. I wish you the best of luck !