Finding your way on the faces of the Coin is confusing for someone coming from an oblate spherical world, such as Earth. But there are cardinal directions similar to those found on fatter planets.
First, you need to understand what face of the Coin you are standing on. The face Stonehell is on is commonly called the Badge, for reasons that are lost to antiquity. The opposite face is known as the Shield.
Regardless of what face you are on, the first axis of direction is in relation to the center of the disk and the rim. Since the sun goes through the center and subsequently produces a continuously moving, molten cylinder of lava along its path, this is reffered to as “fireways”, “bright side” or other mentions of the sun, heat or the center. The rim of the Coin is perpetually cold and frozen with a enourmous mountains of glaciers coating it, so this direction references this. “Iceways”, “shadow side” and othe references to the cold, dark, and edge nature of that direction are used.
The second axis is curved and is in relation to the direction of spin. It is dependent on what face you are on, as the directions are flipped, one side to the other. The directions are known universally as “spinward” and “antispinward” with various dialects changing the exact phrasing.
If you are on the Badge and you face fireways, to your righ is spinward and to your left is antispinward. Facing iceways, spinward is to your left and antispinward to your right. If you find yourself Shield side, facing the sun, to your left would be spinward, and to your right, antispin. Turn around to face the rim and left is antispinward, and to your right is spinward.
These directions mostly hold true when entering the Core, however, the labyrinthine nature of those deep roads make navigation by cardinal direction much more difficult and less useful. None of this even touches on what happens to gravity when you get to the center of the Core…