Free stock photo sites:
Edit photos using Picmonkey.com, a free basic photo editor I've been using for years. The big disadvantage to Picmonkey is that you can't save a design and edit it later. That can be really painful, but if you're just creating simple graphics, adding a layer of text or creating a simple collage (like the one I created above), Picmonkey saves you hundreds of dollars over Photoshop.
It's easier to use than Canva and it has more free features.
Here's a great introductory tutorial: