Need help/hint mapping for mods (Combat, Last Stand, etc.)

Playing the Last Stand mod made me try out the spark map editor. My goal is to create a basic, working ls_map. To figure out what entities need to be placed in order for the map to work I opened the existent ls maps and ls_hellevator. But I didn't find any of the entities I expected to see (after watching Mendasp's basic entity video for vanilla ns2 maps). Is there something I am missing? (Probably yes).
Can anyone please explain to me - step by step - what I need to do to create a map that can WORK in a mod? Preferably use Combat and/or Last Stand as an example.
Thanks!