16 can I still take the professional basketball route?

Yes, many star players change their sports in college or midway, because you may not be able to enter the college physical education major when you go to vocational high school. First of all, you should train hard, participate in some amateur teams and various street competitions, get the results you want, enter some like-minded interpersonal circles, and get to know some low-level coaches. It's all related. I can recommend you to join some teams. As your skills are recognized, someone will ask you to join the professional team. All this presupposes that you have the ability. Basketball is much better in the street now. You can work hard on your physical fitness. It will be easier to find those with excellent physical fitness of the same age, and the basketball ability will be improved faster under the guidance of professional coaches after joining the team. I hope it works for you.