Cloning a TeamForge project in CloudForge is not possible. That is a feature available only on CollabNet TeamForge which can be downloaded at open.collab.net and can be installed on your office network. The instructions for installation and usage of CollabNet TeamForge can be found here help.collab.net.
TeamForge service available in CloudForge is just a sample version of CollabNet TeamForge. Not all the functionalities and features of CollabNet TeamForge are available in CloudForge TeamForge service. CollabNet TeamForge product will fulfill the needs of big enterprise development teams where as CloudForge TeamForge service is mainly used by small development teams.