Thank you for reaching out and extra thanks for using BoldGrid Post and Page Builder for WordPress!
I tried inspecting your site at the URL you sent in the forum but it’s showing an error stating the site cannot be reached. You can change the background image of a section by hovering over the section and using the “DropTab” to change the background for whatever section, row, or column that you’re working with.
Using the “background” tab you’ll have control over background images, colors, animations and so on. I hope this helps!
Please reach back out to us if you have any other questions.