Yes, the camera needs to be loaded with film in order to fire the shutter. When you do fire the focal plane shutter it is going to be loud but that is normal with these cameras.
Google Bronica S2 PDF or Bronica S2 instructions. The original instruction manual is available as a PDF for you to look at. It has instructions and pictures on how to load the film. It may seem daunting at first but the S2 is actually quite easy to load after you have done it a few times. No tricks needed!
The S2 and earlier Bronicas have softer brass gears in them than the later S2a and EC models. Because of this it is recommended to advance the film with the knob instead of the crank so you don't strip these gears.
I used to own an S2a and several EC's. You are going to love that 75mm Nikkor. It's a great lens!