Just bear in mind that you won't touch radio waves until you reach Chicksands after you've been in for a year.
Presuming Morse becomes test-able in training by the time you join (my course are the guinea-pigs) that has the potential to be a bigger hurdle than learning radio theory, dependant on your natural aptitude for it. It's definitely worthwhile reading up on radio theory, but my opinion is that Morse is the most beneficial thing you can concentrate on.
For fucks sake, just chill out and cope with it all when you get there. Thousands have gone through CT training without any prior preparation, and pissed up all the way through the course. Over the last 10 years, it has become a drastically cut down course (a shadow of its former self). Hence the branch is no longer 'technical'.
As for morse, don't worry, I'm sure you'll only be expected to achieve about 14wpm, which is about as much use as a chocolate fire guard. If they're going to teach morse again, it should be back up to at least 25wpm. And they should start doing cyco again too.