So many new TRAINZ novices throw up their hands at the amount of knowledge that veterans have earned the hard way from years of TRAINZ experience. (Experience: The art of making hundreds of errors.)
These tutorials introduce you to the cab, the signals (more or less), signboards (that is, speed limits), the viewing options, the junction controls (hint: the locomotive must be at least 15 meters away before you can switch a junction), turntable handling (hint: tilt the viewing angle to almost overhead to make the rotation controls visible), changing locomotives, using the map (more or less), etc.
Trainz 10 (T10) records your progress in the Achievements choice within the Main Menu. Do the tutorials in the order presented. The initial tuorials restrict some of the variables and controls. The later tutorials open up those controls under the assumption that the prior tutorials properly ended without a derailment.