There is a simple HP printer troubleshooting process you can carry out when you find your printer not printing. Here are some checks you need to perform.

Inspect the connection status between the HP printer and your system.
Check that your devices are connected properly with one another.
After checking this, restart your HP printer.
Switch it off and unplug its power cord.
Plug the cord after some minutes and switch on the printing device.
Now see if the printer is printing.