The file menu is where you can choose to change, save or import projects as well as set the GameMaker IDE preferences. The available options are:
WARNING A warning message is shown if GameMaker detects that the selected project is stored in a cloud storage location. Saving projects to cloud storage may cause problems when saving and building projects. See the Permissions Guide for more information.
NOTE To import a previous GameMaker project into GameMaker it must have been created using the 1.4 version, and even then it may not work directly on import. A great many things are different between GameMaker and GameMaker: Studio 1.4, and so your older projects may need some tweaking for them to work. Please see the article Porting A GM:S 1.4 Game To GameMaker on the GameMaker Knowledge Base and the section of the manual that covers Obsolete Functions and Compatibility Scripts.
IMPORTANT Importing a *.yyz project that contains font resources may require you to "regenerate" the fonts by removing/re-adding them, or by changing the font in The Font Editor and then setting it back again. This is because the existing font information is retained by the *.yyz when it is exported, and, on import later or on another machine, the project may not have the required fonts installed already (or may have a different font of the same name). This should only be done if you are seeing issues with how the font renders after import.
WARNING A warning message is shown if GameMaker detects that the path you try to save the project to refers to a cloud storage location. Saving projects to cloud storage may cause problems when saving and building projects. See the Permissions Guide for more information.