I have an iphone 5s with no service?

I'm an andriod user and my friend sold me his iphone 5s and i'm wondering were to take it, so i can switch to it.Btw i'm with t-mobile for my andriod.

Tmobile will activate it. Ink it with them and get a SIM card. 5s is dual band so that shouldn't be a problem.
Best luck.