You can have a custom desktop background, and you can also use the desktop background as your lock screen or your Start screen background.
To get a desktop background (wallpaper), expand one of the categories in the section below and click the links to preview each background. When you find one you like, right-click on the image, select Save image as..., and save it to a location you can easily remember. Then set that image as your background:
Select Start , then select Settings > Personalization > Background.
Select Picture in the Personalize your background section.
Select Browse photos, navigate to the location where you saved the image and select it, then select Choose picture.