WPBakery Page Builder
Barberry is coming with WPBakery's Page Builder as its page building pluing. It's a premium plugin that comes for free with the theme so it doesn't require a license validation.
For a full guide on how to use the page builder check out the plugin's Knowledge Base at https://kb.wpbakery.com/
WPBakery Page Builder free video tutorials will quickly guide you through everything you need to know about WPBakery Page Builder to create WordPress site. Video tutorials are created in a way that even pro WPBakery Page Builder user or WordPress developer will discover helpful tips and hidden features of the most popular page builder plugin for WordPress.
How to Activate Your Own Premium License
WPBakery's Page Builder plugin comes free with the theme. The license activation option in the plugin is hidden when Barberry is activated and that prevents free users to be asked for license activation at all times, but if you do have your own license and would like to activate it to unlock their premium library and automatic update, you'll have to temporarily deactivate the theme. You can do that by enabling the default WordPress theme, TwentyNineteen for example. As soon as Barberry is deactivated you will be prompted to activate the plugin's license and the License Activation section will no longer be hidden.
You can go back to Appearance > Themes to activate Barberry back as soon as you're done with the plugin's License Activation.