Steps to try in the order given:
1. Reset printer by pressing down and keeping down the feed button whilst printer is off. Turn on printer and the release feed button. No paper feed?
2. Unplug power cord for 1 min. Reconnect and press feed button. No paper feed?
3. Open printer and remove paper roll. Turn printer upside down. Give it a shake to remove any foreign object or debris. Put everything back and test again. Check to see if any paper comes out.