Tap and Hold Background.
Tap “WALLPAPERS“
Try some wallpapers.
You can also set your own photos as a wallpaper.
Tap “My photos”
Select the photo.
Move or pinch or zoom the photo to adjust for your wallpaper.
Tap “SET WALLPAPER“
Select one of the following options;
1: Home screen
2: Lock screen
3: Both
Well done!