Hi,
I would strongly recommend you to watch some basic Cubase video tutorials. On the Steinberg’s YouTube channel, there are planty of them.
As m.c. pointed out already…
- Add and Instrument Track.
- Select Groove Agent SE as an Instrument.
- In the Groove Agent, select any preset (sound).
- Back in the Project window, select the Draw tool.
- Draw an “object” in the Instrument Track over some bars, i.e. create the MIDI Part.
- Select it and open the Drum Editor.