If you have a website with a boxed layout and want to change the background of your website here are the steps to take
Step 1 – In your admin dashboard navigate to Appearance > Customize
Step 2 – Click Theme
Step 3 – Then click on Styling
Step 4 – Scroll down, and under Background Type select Image
Step 5 – Using Select File choose your background image
Step 6 – Click the Publish button (blue button on top) to save and publish your changes