searching detailled doc like how to make one unit attack

Hello,
I'm starting to work on building an starcraft2 IA using pysc2.
I followed the tutorial https://itnext.io/build-a-zerg-bot-with-pysc2-2-0-295375d2f58e.
It's clear but it doesn't answer some important questions.

Is there detailled information somewhere available?
What I want to do is to separate my army in several parts and send them to different locations.
Idem for the drones.

The provided code in the tutorial select the whole army

_return actions.FUNCTIONS.Attack_minimap("now",self.attack_coordinates)
if self.can_do(obs, actions.FUNCTIONS.select_army.id):
return actions.FUNCTIONS.select_army("select")_

Yours sincerely
Loïc Midy