Is there a Cardinal Direction in Unity?

That's a pretty vague question, but yes you can. The same way humans have decided to call certain directions relative to the Earths orientation by certain words, you can call the positive and negative X, Y and Z axis directions whatever you want in your game. You can even create corresponding Vector3 variables so you can directly tell something to look at or move to said directions, e.g.

 public static readonly Vector3 North = new Vector3(0, 0, 1);
 public static readonly Vector3 South= new Vector3(0, 0, -1);
 public static readonly Vector3 East = new Vector3(1, 0, 0);
 public static readonly Vector3 West = new Vector3(-1, 0, 0);