If you wish to duplicate one of the pages in your publication, you need to perform a couple of easy steps for that:
First, you need to create a blank page where the duplicated content should display
Once the page is created go to the Editor and open the page you wish to duplicate
Left-click somewhere on the page to activate the processes, use Ctrl+A hotkey on Windows (Command β+A on Mac) to select the whole page, then copy the selected content with Ctrl+C (Command β+C)
Finally, go open the newly created blank page and paste your copied content on it using the Ctrl+Shift+V (Command β+Option+Shift+V) hotkeys