How to find the generator of an elliptic curve?
If the elliptic curve has prime order of points, then all of its points are generators.


Almost: The point at infinity is not a generator, but (if the number of points is prime) all finite points are. This is a consequence to Lagrange's theorem.


  If so, how can I find the optimized generator (which generates more points) among them?


This does not make sense: Any generator of a group must generate all the points, otherwise it wouldn't be called a generator (by definition).
Note also that generally, the choice of base point does not matter, thus one typically uses random points or points with "interesting" (e.g. small) coordinates.