If I put in my T-Mobile PrePaid SIM card in my unlocked Iphone(works) will it

drain my minutes? It works but will it drain them cause of the internet?
If i choose not to use the internet options on the Iphone will it still drain? Or does it use internet when you turn it on? idk i'm 13 lol.
I FEEL HORRIBLE my parents bought me an itouch 2g yesterday and i unlocked an old iphone 2G (cracked) today. uuhhhh. what should i do?
I FEEL HORRIBLE my parents bought me an itouch 2g yesterday and i unlocked an old iphone 2G (cracked) today. uuhhhh. what should i do?

P.S. It works. I made a call and checked my voice mail and everything.