Fadyef --
Launch Microsoft Project and connect to Project Online. Create a new project and then click File > Save. Enter a name for the project and save it in the Project Online database. This will save the Draft copy of the project. When you are ready to publish your project, click File > Info > Publish.
If you want to create a copy of your project that is only a Draft project, you MUST create the project using Microsoft Project. If you create your new project using the Project Center functionality, the system will both save AND publish your project, which defeats what you are trying to accomplish. Hope this helps.