Where can i buy a used iphone 5c Sim card?

I'm looking to buy a used iphone 5c to use as an ipod but i don't know where to get a Sim card that has been used before so i can activate it. If i buy a new Sim card and put it in will that work? Or does it have To have been used by an iphone before.

No, once a SIM card has been deactivated, it is dead. Plus if it were "live" it would be active on another person's account, NOT yours. So what you do is this, go to YOUR cell phone providers store, ask for as SIM card that works in the iPhone 5C, not sure but I think it uses a micro SIM card. Then it will be activated to YOUR account.

And any other SIM card you are using in another phone will stop working. So if you have more than one phone that you are actively using, they will both need to used the same sized SIM, or you will need an adapter to use that SIM in a phone that uses a different size Sim card.

Why not just buy an iPod touch instead? Much easier & less hassle to get what it is you want out of it.

To answer the question though, it doesn't matter if it is a used SIM or not or if it was used specifically in a 5c or not. What matters here is if the SIM is from the carrier the phone is locked to (most likely).