How do I use my photo for my background ?

Same as before.go to settings

Wallpaper

and choose photo library

Go to the Photos app, select the photo you want to use as wallpaper, and click on the icon at the left bottom of the screen (a square open on the top with an arrow pointing upwards). There you have a menu to share the picture or use it as wallpaper.

HTH

go to

setting

wallpaper

choose wallpaper

tap on the one you want to change and you'll have the choice of included ones or access to your camera roll. then choose your picture from there.

Settings> Wallpapers & Brightness> Choose Wallpaper> Camera Roll> select the photo that you want to use.

you're welcome