I need a little help. Far from a wiz with a smartphone. I got a new iPhone replacing my Samsung SM-S120VL. I'd like to make use of my old Samsung but can't figure out how. How do I find out if it's locked or unlocked? I see cheap pay-as-you-go plans from Walmart but I have no idea what type of service carrier it supports. It originally was from Safelink which I think was Tracfone.