Two things:
(1) Do everything exactly as you did with your instructor.
(2) Don't expect to get anywhere near your planned destination. You'll be diverted part way, and then almost certainly go into general handling.
(3) Try and plan routes that include really clear waypoints (big distinctive towns / motorway or river crossings), and if possible legs that run along reliable line features. It's all part of the game - make life easy for yourself.
G