After activating Businext, you will see this notice:
Click Begin installing plugins. You will be navigated to Install Required Plugins page.
Simply check all of them (or all of required plugins and some recommended plugins you like) and from the drop down select Install, then hit Apply.
When finishing, it should look like this:
Required plugins: Insight Core, Revolution Slider, WPBakery Page Builder
Recommended plugins: WPBakery Page Builder ( Vissual Composer) Clipboard, Essential Grid Gallery WWordPress Plugin, Contact Form 7, MailChimp for WordPress, WP-PostViews, WooCommerce, WooCommerce Smart Compare, WooCommerce Smart Wishlist