Kodak Retina IIIC Manuals 1 and 2
Kodak Retinas are coming from a era where everything Kodak is highest quality , no plastic cameras , plastic lenses but constant race with Germany with again German lenses.
Your camera lens is one of the best and Compur Shutter is very high quality. I dont know these cameras have a light meter or not but Sunny 16 rule would help. Google it. Try to buy two rolls of films and experiment against Canon. I bet you would be impressed.