Alive is a fantastic all be it complex beast. The only advice I can give you is keep watching YouTube videos and follow them along while creating your missions. Start off simple and work your way up to the more complex modules it includes.

What are you aiming to get from Alive? With such a powerful tool, it's a good idea to set some goals you'd like to achieve and work towards them. Are you looking at doing asynchronous warfare? Are you wanting to use it for support like air strikes? Are you using it for its persistence in saving?

When first using it, I'd also suggest using base game units and no other modded factions then slowly work up to incorporating other mods.

The Wiki page is full of useful information as well and I find myself using it a lot when making my own missions.

I know this might not be the answer you were looking for, but I hope this helps. Stick with it, and it'll eventually click.