In this case, it would be better to start from scratch. To run the fresh WordPress installation you can use WordPress Database Reset plugin https://wordpress.org/plugins/wordpress-database-reset/ This plugin will help you to remove all the existing content. Then install the default demo version (WPBakery builder). Then go to Pages > add a new page and import the Banners page, like in this video – https://youtu.be/wkIKN2IyEZI , go to Settings > Reading > select this new page as Home page.
