When I did my Nav exam I had trouble finding the places given on the map, this was because I was reading and using the coordinates given like you do on a walking map. I spent most of my time finding the points and drawing the route. Once I had found and drawn the route the questions were realitivly OK. You will have various problems to solve with the whiz wheel like finding heading and groundspeed and finding the wind strength and direction. I guess you are fully conversant with how to get any point in the triangle with the whiz wheel from appropriate given information if not postpone the exam as this makes up a fair bit of the test. The other thing you will need to know fairly well is the radio navigation theory like beacon types and categories. Think there may also be a diversion related question and one on fuel calculation.
I diddnt use the confuser for the nav as I couldnt understand it though I understood what was written in Thom
Good luck if you know your map and radio nav theory well you should be ok