oh no! Incase you didn't see the tutorial, you move with WASD and shoot with left click :) When you start the game, you are by your house. Move from your house to the start, and enemies will start to spawn :) When you have 5 (or more) gold, you can start placing turrets! Walk over to a turret spot and use either 1, 2 or 3 to place your desired turret :)
If you need extra help, there's a gameplay video you can watch: