You can open the template if you start C2, then go to File > New and scroll down the list to "Template: top-down shooter"
The code you want is the second event in the project:
You can use that but add more bullets and adjust the angle accordingly. So it'd looks something like
[On mouse click]
Rotate bullet 10 degrees
Rotate bullet -10 degrees
This will make it shoot 3 bullets, one straight and two others at 10 degree angles.