Hello,

To add newsletter and social icons in the popup you can use the Wp-Bakery Elements to display them.

To display the newsletter you need to use the text block of the Wp-Bakery and add the shortcode
of your newsletter as in the screenshot.

And for the social icons you can use the social icons element.

Screenshot for Clarification: https://ibb.co/PMt46DK

Best Regards.