Adding a background image and child pages

Background Images

Some themes support full-page background images, while others do not.  Examples of themes that do support full-page backgrounds include Perspective, Persistence, Serene, and Notion.  If you choose one of these themes, you can set the body background image in the Theme settings panel.

With all themes, however, you can assign a background image to a layout block.  When you click on a layout block in the editor, you'll see an option for background image in the settings panel on the right side of the page.

Child Pages

By child pages, I assume you are referring to pages with URLs like these:  /bakery/muffins/blueberry.html .  In Boombox, such URLs are called "paths", but it may help to think of them as folders since they function in much the same way.  These are really only recommended for sites with a lot of pages, because they allow you to keep pages organized by grouping related ones into folders.

To create a new path (such as /bakery/muffins), go to the Pages screen, click the button in the upper right that looks like three stacked dots, choose Add Path, and enter your new path in the format shown.  You'll typically want to select Content for both the default layout and default styles.

Once the path has been created, you can select it using the drop-down menu above the list of pages, and add/edit/delete pages within that path.

Hopefully that helps to answer your questions?  If any clarification is needed, please let us know and we'll be happy to provide that.  Thanks!