By default, the two options Beginner and Professional are available under Tools [Extras] menu -> Select mode.
In Beginner mode, only the most important menus, menu items, toolbars, buttons and context menu commands are displayed.
In Professional mode, all available menus, menu items, toolbars, buttons and context menu commands are displayed (but see the following note below).
Under Section 1.6.8, “Optimize user interface ” in PARTsolutions Administration - Manual you will find a detailed description of the configuration options.