Risks of Giving Out Your Phone Number

Hello :),

I wanted to know the dangers of giving your phone number to people you only know online...
Actually, I've made a very close friend, and I’m aware that it’s still virtual, but it would be easier to talk over the phone... So he suggested it, and I really want to give it to him, but I don’t know the dangers... I’ve been told about the danger of location tracking through phones; if that's true, is it possible to prevent that???

Thanks in advance, I'm counting on you ;)