Your best bet is just to jump in the water. Most students who just do it without thinking of it too much seem to figure it out sooner than others who think way too much.
Just remember that you are talking to another person, in english, on the other side of the line. The lingo will all fall into place with time. If you spend too much time and effort trying to ‘prepare’ for it, I can guarantee that you will have more trouble (you will overthink it and try to sound like what you heard earlier).
A good rule of thumb that you can use is to break down each radio call into 4 parts:
Who are you calling?
Who you are?
Where you are?
What you want?
Make a habit of always including these 4 parts into each radio call, that’s pretty much what ‘pilot lingo’ is… just saying those things in that order.