Jetman12
Don't get too hung up with Grid Navigation and Polar Stereograph questions early on in the course. I did and wasted a lot of time. If you are finding them tough to crack, just move on and re-visit them at a later date.
By the time you go back to them, you will probably have completed a lot more of the Gen Nav material and they will become a lot clearer. Incidentally, there wasn't a single question on Grid Navigation and Polar Stereograph in my exam.
The same goes for pretty much anything that you are struggling with and remember you can always make use of the instructors/forums for DL courses.
A lot of people find Gen Nav tough early on, so don't get too down about it.
Good luck!