Check out this tutorial to learn how to copy, paste, and duplicate your objects in Prezi:
Click on the text or object that you wish to duplicate.
Press Ctrl+D (command+D on Macs) to duplicate it.
To copy or duplicate multiple items, hold down the Ctrl key (command on Macs) and click on each item, or hold down the SHIFT key and drag your cursor around the objects you want to select.
Copying and Pasting within a prezi:
Use Ctrl+C (command+C on Macs) to copy any object or piece of text to your clipboard and Ctrl+V (command+V on Macs) to paste into your prezi.
Copying and Pasting between prezis:
You can also paste content from one prezi into another using the keyboard commands above (it doesn't matter if you close the prezi you are copying from before you paste into the second prezi). Note: If you have added path steps or animation to content, these will not be retained in the prezi you paste your content to.
Copying and Pasting between Prezi's online editor and Prezi for Windows / Mac:
Copying from an online prezi to one opened in Prezi's desktop application (or any other application such as MSWord) and vice versa is not supported. You can copy/paste from one online prezi to another and between one prezi opened with Prezi Desktop and another.
However, you can copy and paste raw text between prezi and other applications. To copy text from a prezi: double-click on the text box, then select the text and then use Ctrl+C (command+C on Macs) or the right-click menu to copy.
Alternatives to copying and pasting.
Sometimes copying and pasting might not be the best choice for what you want to achieve. Remember that you can always use Prezi's Object Library feature to save your favorite content elements. You can also duplicate content using the ctrl+D (cmd+D) keyboard shortcut.