A site can have multiple subpages, which can then be added with different types of sections (grid, PDF embed, image slideshow, video playlist, and text).
If you need to delete a subpage, be careful, as you might not be able to restore it to your site.
To delete a subpage:
From the site editor's left sidebar, click the "Edit" button next to the subpage.
Hit the red "Delete Subpage" button.
Confirm this command by clicking the "Delete Subpage" button in the pop-up dialog box.
Note: A subpage cannot be deleted if it's the only subpage for the site.