How do I assign drums to the pads/keyboard

I just want to know how to assign cymbal and base drum to certain pads, certain notes on keyboard.

You can use Cubase’s drum maps and drum editor to change the I-Note. This way you can for example play a crash cymbal with A4 without changing anything in Groove Agent.

In Groove Agent SE 4, you can also remap the notes by clicking “Use Hardware Controller Mapping” and then right clicking the pads.