Hello @Gooliart,
I would recommend you to create a new topic for your questions. Here are settings of the demo – http://prntscr.com/jbvwwj https://www.8theme.com/demo/xstore/burger/wp-content/uploads/sites/53/2017/10/bg-site.jpg Via Theme Options > Styling > Content you can set own background image or color.
Regards
