Delete blank pages in pages document

There are two styles of Pages documents: 1) the default word processing document, and 2) the optional page layout format. See Intro to word-processing and page layout documents in Pages on Mac - Apple Support

Only a page layout document allows you to remove pages by right-clicking on the page thumbnail and choosing delete. For the standard word processing document, you must select the entire content on the page to delete, and then backspace twice: once to remove the content, and to remove the hidden page break.

Apple provides two different blank templates depending on your word processing or page layout intention: