Here are some phone wallpapers I've made/used. Some are from my quite old smartphone and may not be the correct size/ratio for today's phones. You could still use them though, they might just be cropped differently. Click on the photo, it should come up in a window, and right click to save. Transfer to your phone, go to your gallery, and however your phone does it, choose "set photo as" and choose how you want to save it (as home screen, lock screen, etc.). The files are fairly large, and I don't know if it's just my internet or not (it's pretty slow) so it takes a bit to load.