Re: Gameplay
Please show us a screenshot, or post a link to a recorded replay video that you can upload e.g. on YouTube.
At the beginning of a battle, you can only build 1-2 units. For every unit more that you want to build, you have to wait some time. This is called "population cap" and it applies to both players, of course. The point of this is to prevent spamming many cheap units at the beginning of a game.
Note that in some of the events, the rules for the population cap are less strict, and there you can indeed build several units at once right from the start. Showdown is one example for this.