To find out about parts needed, look at
Hulls and click the "shafts" tab. Although it describes scratch building, the principles and part names are the same.
When you buy a prop shaft, you normally get the actual shaft along with an outer tube fitted with bushings. The propeller fits on one end and SHOULD BE SECURED WITH A LOCKNUT. At the inner end, you usually fit a universal joint which goes between the inner shaft end and the motor shaft. Most makers have options to give the appropriate sizes of hole for the shafts.