When a closed curve is parameterized by {x[t], y[t]}, then as you advance along the curve in the direction of the parameterization, which way do the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point; in the direction you are going, or in the direction opposite to the direction you are going?

In the direction you are going,

Explanation:

We know that the tangent to  {x[t], y[t]} are  {x'[t], y'[t]}. Since  {x'[t], y'[t]} are tangents at  {x[t], y[t]}, we know that the tangent at a point is always parallel to the direction of the function at that point and in the direction of the function. So, the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point in my direction of motion as I move along the curve.

So, the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point in the direction you are going.