It is recommended to run import on a fresh WordPress installation. For this you can use WordPress Database Reset plugin https://wordpress.org/plugins/wordpress-database-reset/ The plugin can be used to remove all the existing content and install a new version (in your case, Default demo with WPBakery builder) from scratch. It is recommended to disable the theme https://prnt.sc/unle03 before the reset.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.