Hi, It's commonly known that the older you are, the more difficult it is to become a native speaker. Given the fact however that you're only 16 and - as far as I can tell - know a quite a bit of English already, you stand a fair chance of developing a very natural sounding accent. Meeting new people, making friends, using the language as much as possible and attending school should do the trick.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.