Iphone 5 found unlocked clean esn?

So i found a iphone 5 with a SIM Card… I unlocked it myself and it saids its clean esn but to continue using it i need to put in the SIM card. I don't know what to do next. I want to use it as my cell phone, how can i do that? If i put in the SIM to continue will it get tracked? I'm scared because i don't want to get in trouble i just want to use it for myself. Any Information would help me!

Well as long as it has a clean ESN and the original owner doesn't report it as stolen, then yes you can use it. I would actually get rid of it by selling it now while it still has a clean ESN… It's only a matter of time before the owner calls there provider to report it as stolen.