sheriff3: the ROTC introductory academic class at UCF is open to any student (It will probably be called something like Leadership) and would be paid for just like any class there… part of the quarter/semester payment that takes care of anywhere from 12 to 18 units on a flat rate basis. Universities don't charge per class or per unit anymore… other than community colleges (JCs).
If by "enrolling in the class" you mean joining ROTC (which is Class, Lab, PT, etc.), then there is no "ROTC" charge… just the class fee that I mentioned above is already included in your Semester payment to UCF.