Every scene has its own background that you can change in Scene Settings under Scene Background. You will see a Library of available backgrounds. And you always have the option to import your own background to use in a scene.
You can also change Scene Background Color to customize your scene even more.
More about Scene Settings you can find in Scene Setting Article - link here- https://secure.helpscout.net/docs/56d5bb3b9033601bde8baf6f/article/56fd1bacc6979111dc39a6eb/