In these maps your main weapon is AC (anticreeper), you use terps to make AC go to correct direction/area.

List of first few CSM maps

CSM mapmaking information

This CW3 map will teach basics about mode.

https://knucklecracker.com/forums/index.php?topic=27739.msg168593#msg168593

You can find it from Colonial space with search.

Also, official forum post has more information: https://knucklecracker.com/forums/index.php?topic=28617.0