How does height (or generally the way one looks, or how old one is)

It doesn't influence success all that much. Frankly, the only time it matters is if there are other guys attracting her attention in the immediate vicinity who are taller/younger/richer/etc. AND have a personality edge over you. If you find yourself in those types of situations too often, you need to improve your personality and charisma or change your environment when finding women to pick up.