Did it make calls in the past?
I would first try holding down the power on/off button (upper right corner) and the Big Home Button in the middle of the phone together until you see a white apple logo on the screen.
Then release both buttons and let the phone reset. See if that fixed your issue.
f it did not do the following.
Take the SIM removal tool that came with your iPhone 5s and carefully remove the Sim card (While phone is off) wait a few minutes and place it back in the device.
Turn on the phone and then test the call
if you are still having a problem call 1-800-922-0204 from a different phone and speak to customer service.
You can also visit any Verizon Wireless Corporate Store to have them look at it. If they need to replace the Sim they have them right there for free. Do not go to any reseller.