Changing your background is extremely easy in Total and you can actually set it both globally and also alter the background on a per-page or per-post basis.
1. Global Background Setting
Via the Customizer you can quickly and easily change your background. Simply go to Appearance > Customize > General Theme Options > Site Background.
2. Per-Page or Per-Post Backgrounds
If you want to alter the main background on a per-post or per-page basis you can do so as well via the built-in meta options (custom fields). Simply go to the page or post you wish to edit and below the editor (or somewhere on the page depending if you moved your modules around or not) you will see the page settings metabox where you can click on the “Background” tab to easily alter your background.