The project's property window is displayed if no object is selected in the workspace.
The project properties are also available as fields (see Overview of Fields) and can be evaluated with the ProjectParameter$() function.
To copy the path of the currently opened project to the clipboard, right-click the "Project" item in the "Objects" tool window and select "Copy Project Path" in the context menu. This function is also available in the context menu of the workspace when no object is selected.