Hi, thanks for posting.
The home page is built with Page Builder by SiteOrigin and Black Studio TinyMCE. If you have both of those plugins activated, go to Settings > Reading and assign a static home page. Next, go to Pages and edit that page. Click the Page Builder tab the Layouts button. Choose and apply the default home page layout. Once added, edit the Page Settings in the right column, set the layout to No Sidebar.
Hope that helps 🙂
Ref: https://purothemes.com/documentation/ultra-theme/