Hello,
if you don't have any experience with a Rolleiflex or other 6x6 cameras, it would be the best to look for an instruction manual (for this you should find out the exact model by the serial No.). There you can see how to load and unload the camera and how to use it. Perhaps you know somebody who owns a Rollei and can explain it to you. Rolleis are not complicated to use but there are some things to know.