ArmA 2 Mission Editor for dummies?

So, I recently bought Arma 2 off steam because it was on sale (before anyone asks, I can’t run Arma 3 or Reforger). One of the main reasons I bought it was because of the mission editor and what you could do with it. Needless to say, I’m utterly clueless with how it works or how to use it. For a starter, I wanted to make a simple heli assault and landing on Utes. I was able to get the heli’s in the air and moving but I can’t seem to get any of the troops to be organized beyond basics. Then I tried some patrol ambush on Takistan (FYI: I own both Arma 2 and OA). Again, didn’t work. Basically, I’m just asking for a barebones tutorial on how to set up missions in Arma 2.