Everything I try to print (pages, pdfs), it will print random characters/symbols. Any idea how to fix this? Using recently installed version of Freya.
Accoring to the official HPLIP-homepage your printer needs al least HPLIP version 3.14.10.
Unfortunately elementary OS only provides HPLIP version 3.14.3 in it's repositories.
You need to install the latest version of HPLIP in order to get your printer running. I'd suggest you take a look at godslayer_69's answer to a familiar question, the installation seems to be a little bit tricky.
Seems to be printer issue according to hp.
Got this from this page here: Continuous Pages of Strange or Garbled Characters Print
Communication issues between a computer running a Windows operating system and your HP printer might result in pages of garbled text that look like gibberish, or nonsense, or the letters could be scrambled. The text might include a partial page or a full page of random or unrecognizable letters and numbers. This issue is not related to ink or print quality. Do not perform common print quality troubleshooting steps, such as cleaning the printheads.
Hope this helps.