Kenny... be careful. I have not seen a simulator yet which anywhere near approaches the "real" thing. They can't because it is impossible to feed instructions into the simulator at the sort of speed you need in a busy sector. Heck, even the "real" simulators have trouble coping, and they have proper blip drivers! How do you simulate co-ordination with adjacent ATC units, coordinators and other controllers alongside you? You only hear part of the job on the R/T and there's as much again, if not more, going on in the background.
I had 37 years "IFR" experience, most of the time at Heathrow and the Heathrow sector at London Control, and would advise you that the best approach would be to learn from your instructors when the time comes. By all means get the manuals and mug up on the separation standards, types of airspace and facilities offered by various ATC units, etc., which will be of great help. However, I'm concerned that messing about on a toy simulator without a professional instructor might do more harm than good.
Lastly, a friend of mine was a 747 Captain.. He had great trouble landing the 747 in Flight Sim, yet I could manage it 5 times out of 10 and I've never flown a real plane in my life. On the other hand, he did pretty well with the TRACON ATC sim... and I spent all my time getting airmisses!!!