The War Boxes game is unlike any other tower defence game. You will not be able to see a tutorial that will show you how to play the game. When you hit the start button, the first thing you'll do is choose the place where you'll defend your fortress. Then you choose the turret that will accompany you to fight. To begin, you'll have the rifle at your disposal.
Other turrets in War Boxes, however, are locked first. To utilise resources, you must first earn them.