WPBakery is a page builder that is meant to work in the content area of the page. Editing the header and footer of your website is typically done through the theme. The options available for editing the header and footer will depend on the specific theme that you are using.
For example, if you are using the Visual Composer Starter Theme, you can edit the header and footer of your website within the Theme Editor. To get started, first, install the Visual Composer Starter Theme. You can do this by uploading the .zip file under Appearance > Themes > Add New > Upload Theme or by searching for the theme directly in the WordPress repository and clicking ‘Install’ under Appearance > Themes > Add New.
Activate the theme and click on ‘Customize’ to access the customization options. There you will be able to customize the style, color, padding, and stickiness of your headers and footers according to your preferences.
If you’re still unsure about how to edit headers and footers, it’s a good idea to check the theme’s documentation or contact the theme creator for more information.