If you would like to duplicate a Page or Post, you have two options depending on how the Page or Post is set up.
If all of your content is in the WordPress Editor, go to the HTML (Text) tab of the Page or Post and copy all the HTML code (see how). Then open up a new Page or Post and paste the HTML into the Text tab.
If you've built a Page or Post in the Builder, it's easier to duplicate it. Scroll down to the Themify Custom Panel and hit the Duplicate this page in the Themify Builder section.