How can I save my models?

Select (in the upper left hand corner) File-->Save All parts, assemblies and workplanes in the active session will be added to the list of items to be saved. Use the browser to select a location to save to on your hard drive. If you have only 3D data, check to make sure that you save as a file type .pkg. If you have both 3D data and a 2D drawing, check to see that your file type is set to .bdl Enter a file name in the filename section