Can I trade in devices and games in gamestop?

I'm 17 years old and I'm wondering if I can trade in games and devices at gamestop, I wanna trade in my iphone that my ex girlfriend gave me, it's in perfect condition. Any tips before trading it in, and do I need a parent to trade it in?

You have to be 18 or bring a parent.

Yes. As for the 18 year old thing, i don't think that's the case. I went in once and traded 3 games when I was 9