There are tutorials within RANT which are pretty good, so working through those would be a good starting point.
Having said that, if you can find an Instructor who is willing to help it would always be beneficial, particularly if he/she will be the one training you on the a/c. Maybe difficult though, the instructors who trained me for my IR were great but nether were keen on RANT, though personally I thought it was excellent, and still use it for practise approaches from time to time.