Adobe is giving away free copies of the entire Adobe Creative Suite 2 via their website for a limited time. The only catch is that you will need to register an email address with Adobe. The product is about 10 years old, but even the CS2 versions will still be useful for most of us if you don't have a newer version.
Follow this link to get your free copy
https://www.adobe.com/cfusion/entitlement/index.cfm?e=cs2_downloads (https://www.adobe.com/cfusion/entitlement/index.cfm?e=cs2_downloads)
CS2 was what I learned Photoshop on. It's a great deal for someone who doesn't have Photoshop.