You have to aquire the knowledge to answer the questions on the test. It doesn't make any difference how you get that knowledge, classes, books, internet, whatever, just so long as you can answer the questions. No, you don't have to take a class. Although, that's the easiest way sometimes.
Once you get that out of the way, then you need to learn to use the radio you get. That means read the manual and understand what it's telling you. most radios are not all that simple anymore. If it has bells-n-whistles then you gotta learn to 'play' those things, you know? It isn't impossible by any means though. When all else fails, read the instructions.
It's a good idea to listen to what's going on and -how- it's being done. Then you'll have some idea of how to go about stuff. Everybody starts of not knowing how to do things so don't think that it's just you. If you don't know what or how to do something, ask. Everybody goes through the same thing so just give it a shot.
Good luck.
- 'Doc