Remember, the key is being able to work with images that have a transparent background.
Canva's background removal tool is for upgraded members. Find a free program to remove backgrounds, such as Pxlr.com (Express version), where either the program removes it or you complete this manually.
Try DeepDreamGenerator (image filtering program). They have awesome filters you can apply to free-sourced images.
Take care. Can't wait to see you first project. Take care and have a good rest of your week.