Can someone track you by your number?

Okay a couple months ago I made a friend on a virtual website. I'm 15, he's 15 too. Btw before you ask, NOOO he's not a perv or has asked me any kind of personal questions. Well, we've gotten to be best friends over the months and I wanna give him my number to text me. If in the worst case scenario he was bad, could he track me? And btw, I honestly don't think he's bad I've seen baby pics of him and a couple regular pics of him and he doesn't ever ask inappropriate things. Thoughts?