What are you tying to edit? Is it a photo, a drawing , text or a combination of both?
If it is a photo any photo editing software will work.
If a drawing a paint program.
If it is text you need to scan with OCR or ***Optical Character Recognition*** sofware to convert the “image” into a text document.
For a combination of both you will possibly need all of the above.
Look around there are good sources of Mac OS free software. The installation disk for your all-in-one printer may have some examples.