Delete Page Or Subpage. Delete each page by hovering over its thumbnail and click the trash icon. Select and remove the PDF pages you dont need.
Ensure that Live Edit is On. Click Unhide for the Page or Subpage you want to unhide. Select Unpublish All Versions.
Sharing or not sharing keeping private a Page or Subpage has to do with controlling access for others to Pages and Subpages you manage.
On a computer open a site in classic Google Sites. At the top right click More. Tutorial on how to add and delete pages and subpages to your Google Sites. Click Unhide for the Page or Subpage you want to unhide.