Question: how do you change your background on an ipad?
Answer: Go to Settings > Wallpaper > Choose a New Wallpaper.
Do one of the following: Choose a preset image from a group at the top of the screen (Dynamic, Stills, and so on). Wallpaper marked with. changes appearance when Dark Mode is turned on. ... 
Tap Set, then choose one of the following: Set Lock Screen. Set Home Screen.