Sausage factory training academy... fortunately we have ADSB to see where they actually are in the sky!
CTA endorsement also requires completion of a written test; its not a big test; more to ensure the student knows correct procedure and which publications or sources to go to to access information.
Being able to competently maintain required altitude level and execute Tower vector and altitude change instructions upon request without delay is also required.
Some ATC's speak really fast and its difficult to get it all; so just ask them to slow down and repeat request. Listening to coms between IFR and Tower is often lightning quick; the coms being heard are mandatory procedural with both ends knowing beforehand what the communication and response is going to be. Listening to LiveATC website is a great way to become accustomed to the ATC environment; tune into Bankstown or Moorabbin for an hour each day or so for a week and listen to Tower and Ground op' frq's. By the time you take your checkflight CTA environments will feel more natural. It also gets you accustomed to "what" information to include on readbacks.
Dont forget the all important notepad and pencil to write down squak codes, flight levels, vectors, taxi ways, and runways when ATC provides requests; and have a detail ground map of the airfield at hand to refer to.