Thanks for playing. Not sure how else to do it without left select and right action, I had left select and right cancel on previous demo but it was too restrictive. Eventually I think there will be a context menu when there are multiple options for an action like move or attack.
If you find it too hard, gather resources straight away as there is enough on the map to build 1 of everything. Build an archer tower to protect you in the first waves of goblins and give you a safe zone in the corner.