You can use either 120 roll film or 220 roll film for this camera.
Unusually for the twin-lens reflex camera, C33 takes the system of sending a film paper from the bottom to the top. So loading a film is rather easier.
Put a spool in the top room (in the picture : the left) and a film in the bottom room (in the picture : the right).
When you do this, pull out the spool changing knob which are both sides of the lens changing knob and turn them. That makes easier to load a film.