In central Europe and Japan, middle C is usually called C3 instead of the C4 that you’re probably used to. In other words, in Cubase, Groove Agent and most software from these regions B1 will be B0, A1 will be A0, etc.
By clicking the keyboard icon to the top right of the window you can see which keys trigger patterns and which trigger solo drum hits. If your MIDI output is set to “Groove Agent - Main” both patterns and solo notes can be played from your keyboard.