DOSWS62002

what do mean reset it, like hit where it says restore to factory settings?

Hey, I just got the Avic D3 headunit and put it in last night, I bought it about 6 months used off a kid that works with me, now that it is in my car with the navigation on, ok so say im on a road driving North, and the arrow is moving on the screen north, but the point of the arrow is facing the other way, do i have to change a setting or is there something I did wrong....help please. thanks.