I just got this game and started playing, I just became a level 10 sith inquisitor. I wasn't even aware I was able to pick an advanced class yet... I don't remembered where it was on the HUD, but look around at your display, there should be something on your HUD that might be yellow or something, click on it and it will bring up your advanced class selection. Once you pick a class, the moves trainer will allow you to learn your advanced class moves as well. Hope that helps you out.
