I've started up the demo and I've been following the tutorial. The first mission (Naivety) takes a while to beat, and when you move on to the next mission (Indelible), it's easy to forget about how to place the HQ, because it's a separate button from the other units.
It would help if more of the tutorial missions pointed at the HQ button with an arrow, so new players don't forget about it and get lost.