Simple. Head into Walmart and buy a cheap prepaid phone and sim kit for TMO or ATT. Often $15 and include some starter minutes (only TMO).

ATT has better coverage.

Activation takes only a few minutes and you get to pick the area code and town.

If you don't need the phone, sell it or give away (I'll take it).

BTW, I've used TMO prepaid for years and love it.