A:AnswerYou have to buy a mobile data plan from a carrier like (EX:) AT&T or T-Mobile they will set you up with your mobile data plan and your phone number
A:AnswerYes! My mom purchased the SE and the Best Buy guy transferred everything from her iPhone 6 to the iPhone SE. Was pretty simple to do. She didn't have a lot on the phone as I backed up all her pics to Google Photos prior so it was really her contacts and all apps that were moved.