Press space to look through the images, then go into backdrops and they're ready to use (i tested them all out, they will also work for studio thumbnails. I'm okay with you guys using them, since i really don't care, they're just images
Most of them are snip-its from google and/or YouTube. If you want to do this, you can try this shortcut: [Windows key]+Shift+S. know that it doesn't work on all PCs. You can also use the Snipping Tool app.