Helpful hint no.1
The aim at all times is to make sure you and ATC understand each other. If it all goes a bit pear-shaped, forget what the comms book says and just use plain language to get your message across.
Like anything else in life, and especially aviation, a lot of it won't make sense to you right now, but with time, practice and good instruction it will all eventually fall into place.
There are a surprisingly large number of commercial pilots who have very poor R/T skills (worryingly bad in some cases), and these guys are way beyond the circuits stage of their flying careers, so don't get too hung up on it just yet.