Thank you for this updated information.
Make sure you have performed all the Apple updates on your computer. Please follow this Apple document here.
Now, try repairing disk permissions, I will provide a Apple document to help you here.
Next, try resetting the print system on your computer. I will provide an Apple document here to help you.
If you have a USB cord on hand, try connecting this to your computer and printer. Try printing a document to verify if you're experiencing slow printing.
Please post your results!