Place the cursor at the end of the content on the first page
Press Backspace or Delete to remove the page break or extra paragraph marks
Turn on Show/Hide formatting marks with Ctrl+Shift+8
Delete any manual page break on the second page
Delete extra blank paragraphs on the second page
If the second page is caused by a section break, delete the section break
If needed, reduce the font size or spacing of content pushing text onto the second page
If the page is still blank, go to the second page and select all visible marks, then delete them