Generally speaking think of X and Y as North and South as you look at a map.
When you spread a map out on the table in front of you.
The X is East and West, as you move East that is the Positive (+) X direction.
As you go West that is the Negative (-) X direction.
The Y is North and South, as you move North that is the Positive Y direction. And South is the Negative Y direction.