You can change the background image (wallpaper) that displays on both the iPad’s Lock screen and Home screen, and it’s very easy to do.
Open the Settings app and tap Wallpaper, followed by Choose a New Wallpaper. You can choose from Apple’s default images at the top or scroll down to select one of your own pictures from Photos.
You can then adjust the image by moving and zooming it until you’re happy with the placement.
When it comes to Apple’s images, you have two options to choose from. Dynamic wallpapers move when you tilt your iPad. Stills, on the other hand, include wallpapers which change their appearance when your device switches from Light Mode to Dark Mode (and back).
From the options at the bottom, select if you want to use this image for the Lock screen, the Home screen, or both.