How to get a sim card for iPhone 4?

My dad had just upgraded to iPhone 5 and he's handing down his iPhone 4 to me, my friend has an iPhone 4 w/o data on AT&T and I'm wondering how do I go about requesting a sim card. Do I go to the store? Do I have to order online? This would be without data while other people on my plan do have data. I'm always home so I figured data is useless when I have Wi-Fi.

Go to the store, they will support you.

wkr p

I don't know about the no data part since, it is a smartphone & data plans are mandatory for them particularly on AT&T.

As far as getting the SIM just go to an AT&T store & get it.