If you’d like to duplicate a single page in your yearbook, the easiest way is to save that page as a template. Follow these steps:

Open the page you want to duplicate in the designer.

Next, beside the Save button, click the down arrow and select Save Page as a Template  

In the Template Type field, select Standard Template.

In the Pages field, select the page/pages that you want as a template. It could either be the left, right, or both pages.

Give your template a name and click the Save button.

Your saved page template will now be available under:
Layouts > My Templates > Templates 

From there, you can apply the template to any other page in your project.