I'm a tad surprised you haven't at least got a basic grasp on it nearly at CPL. I thought most (if not all) the schools at MB would have some GPS equipped aircraft?
Anyway, if it's a GNS430 unit you are expecting to use you can use this trainer:
Garmin: 400 Series Simulator Updates & Downloads
For use as a supplement to visual navigation the Garmins with displays are extremely easy to use and you should pick it up in no time
