Take out all the ink cartridges, shake them and put them back in the printer. Make sure they are secure. Then try to print. If that doesn't work, you might try unhooking your printer from the computer or tower, turn off and let it set for 5 - 10 minutes to reset it.
Have you gone online to troubleshooting HP printers? There might be other suggestions.
Computers and their accessories can be so frustrating!