DP,
I think you have done well to post your questions here and shows the right sort of attitude to become a pilot.
Hopefully other's comments here have been a help. Getting practice on the radio is hard, especially when you are not flying in and out of controlled airspace or using radar services. It is debateable whether it is better done in the air or on the ground. I personnaly believe it is best done for real.
Chat with your instructor about it, do the mock test and see how you get on. The important thing to remember is to think before you push the button and use things like TRPACER (ask your instructor). Relax and try to enjoy. There isn't that much you need to say.
And in case it all sounds daunting, and everyone else seems to know far more about it than you do, it will be all changed in March next year, so we will all be having to learn it all over again.
