Fast guide on How to play the game For Beginners.
First start a match. Wait for your turn. If Campaign map, you will always be the first player.
Go to a Barracks or other Building that can create Units (Airport or Seaport). Press "X".
Choose your Unit and, if you have the money, it will be Built. Go ahead and create as many Units as you need.
When you have finished building your first Units. Press "ESC" to finish your turn.
Wait for your Opponent(s) to finish their turn. Then you can move your Units. Press "X" to select them and then select an available terrain to move (they are marked with a white square).
With Foot Soldiers (Infantry, Engineer, Sniper and Flammer) you can capture buildings. Just walk on them.
You can also attack other Units. That's the Basic Mechanics of the game. I'm sure you will enjoy it!