Trying to learn to edit photos, any ideas?

Hello everyone! i'm a cosplayer, and lately I've been thinking of trying to get into doing photoshoots for my fellow cosplayers, since when I take some pictures for my friends they compliment me and I want to try to get better (please give me some recommendations for low budget cameras please). Since I'm interested in this I've been trying to edit my own photos... Failing miserably, ehe. The thing is that I don't even know where to start and more importantly I don't know on which software I can rely on for good photo editing. Any tips?