I bought a new iPad from Verizon because they still had them available. I presume it came with the Verizon SIM installed. But now I think that AT&T may be the better choice for my data provider. Will it be a problem to have it switched? I have not signed up with Verizon yet.
The Verizon iPad will not work on the AT&T network and vice versa. You will need to return the iPad and buy an AT&T model from AT&T or Best Buy, or from Apple, either in a store or online.