In the FILE menu there are the classic File → New, File → Open... and File → Save items. When opening or saving a new file, the file dialog defaults to the directory that you put in the “Initial path” text box in the Preferences dialog, usually the user home directory.

The File → Generate code item produces the code from the current design.

In the VIEW menu, you can show or hide the tree window and the “Properties” window.

In this menu you access the Preferences Dialog as well.

The HELP menu provides access to the wxGlade user manual (this documentation) as well as to the “About...” dialog.