If the SIM card is not inserted or seated properly, this risks causing phone to only allow calls to 911. Ensure SIM card is securely inserted into the slot. It may not hurt to remove it and re-seat it. Make sure it's correct side up.
How do I turn off emergency calls only on my Android?
To turn off Emergency Mode, try these things: Press and hold the END button (or the button you use to end a call) for 3 seconds. Turn your phone off and then on again. Reset your phone (see Troubleshooting your wireless phone)