Crello is a free platform that bears a striking resemblance to Canva. Like Canva, Crello offers a variety of free design templates that you can customize with stock imagery and clip art or with images of your own that you upload to your Crello account. All of your designs can be downloaded as PDF, JPG, or PNG files to re-use as you see fit.
Applications for Education
Crello is a tool that you could have students use to create posters, infographics, and collages about the subjects that they research in your class. You might also use Crello to create graphics to share on social media to promote a school event. I published an extensive post about using graphics to promote school events.