First step: Choose your post types
The Creative Grid for Visual Composer plugin can be used with any WordPress post type (including pages and post types created by themes and plugins) except blog posts and WooCommerce products. But before you add the plugin's element into a page using VIsual Composer, you need to choose the post types first on the plugin's Settings page.
After you install the plugin, please, go to "Settings - Creative Plugins" in your website's admin panel.
Check the post types you want and press the "Save Changes" button.
This is optional but you may want to use some unique meta data from the post types you've chosen to be used as "Title" and "Additional info". Just check the "Extra sources". Later if you feel you don't need it, just uncheck it.
Now you are ready to use the plugin.
By the way, you can create a new post type too. Find more information here.