Since you have an AT&T phone, all you need to do is pick one of their compatible MVNOs and obtain a SIM. This can be done online, even through eBay for most of those companies. You can also get H2O SIMs at Best Buy. There's no info involved, unless I'm really missing something.
They don't ask for your cc infor because it is prepaid. If the money runs out it stops working , if the due date comes due and it isn't re upped it again stops working. There is no calling them up and saying I will pay next week like you can with a contract phone. There are various ways to re up. Via online sites with the credit card if you want, some at various gas stations and stores for cc or cash. Airvoice can be re upped at western union. So there are plenty of options.