The full version of WPBakery Page Builder (previously known as Visual Composer) comes with this theme. You do not need to activate a license to use it.

Free updates for the plugin will be included whenever the theme itself is updated. So after updating the theme you will see a notice at the top of your backend pages to update the WPBakery Page Builder if necessary.

You only need a license for two reasons:

1) You want to receive automatic plugin updates directly from the WPBakery developers rather than waiting for them to be included in a theme update.

2) You want to access the Template Library for additional page builder templates.

To get a license you need to purchase the plugin yourself.