There is no AI at the moment, they are empty placeholders for now. Functional AI is probably 2-3 versions away still. There is an AI called "Swarm AI", which just sends waves of units towards your base.
Collecting supply is automatic, but the path finding is a bit wonky right now and the supply trucks can get stuck. Supply is displayed at the top of the sidebar UI.
But yeah, right now its functional but not really playable. Lots of bugs too. Will be better in a few more versions.
Thanks for playing!