Hello,
When you first start SAM, it displays the Welcome window, where you can choose to either start a new project or open an existing project file. After you start or open a project, you will see the SAM main window, which has a file menu, where you can find commands for saving and opening files, among other things. If you try to close a file without saving it, you should see a message giving you an option to save it.
SAM stores files with the .sam extension. When you save a file, you should find it in the folder where you saved it.
Please see the Getting Started and Reference sections of SAM's Help system for more details about how to use the software. You can open the Help system by clicking the Help button at the top right of the Main window, or the Help contents button at the bottom left of the Welcome page. You can also press the F1 key in Windows or Linux, or Command-? on a Mac to open the Help system.
Best regards,
Paul.