If you're looking for a Photoshop-like image editor that's free, check out GIMP at gimp.org. There are versions for Windows and OSX, and good basic documentation and tutorials available online. I found the GIMP Quickies particularly useful when I needed to figure out very simple things like making files smaller for more efficient uploading. And you can't beat the price!

As much as I like your current photography subjects, I think it's great that you're challenging yourself to move out of your comfort zone and explore new subjects and skills. I don't have any brilliant ideas, except maybe photographing more people, but I wish you all the best in this project!