Iphone 5C Sim Card Activation?

I recently ordered a unlocked iPhone 5c, I need to stay in contact with my parents just for this week until I buy a Sim Card, therefore I'll be using my icloud on iMessage and factime audio. I'm stuck on the Sim Required screen so would anything bad happen if I just stick in my friend's Sim card, go through the activation and give it back?

Nope, nothing bad, you can even use an inactive SIM card, it's just a requirement for some reason.

Nothing bad will happen to the SIM card, to your friends phone or to the iPhone once you take it out.