Nice entry ! I really like RTS games, good job ! Some already mentionned it, but I only had some trouble with the selection. It seems hard to implement though !
As a little quality of life change, I had trouble finding the units without weapon for example. The fact that you can see all the units in the bottom bar, and select one was super useful for this, maybe adding little icons to say 'this one got a weapon/armor already' could be cool !
Again nice first game ! Congrats !