I am 24 years old and I have no hair on my face, why?

Facial hair growth is a genetic trait.  If you have very little facial hair there isn't much you can do to increase the growth.

Why you aren't seeing results also takes into account what age your relatives started growing fuller facial hair. But also some people are just lucky or unlucky depending how you see it. If it isn't a hormonal or age issue it likely is nothing you can easily change, and may have to get a transplant to grow the facial hair you want.

Many young men want to accelerate their beard growth and ask about it. It takes age (genetic triggers which occur in family lines) so if you want to find out when your beard will grow out, you need to find out when your father or grandfather started to grow their beard. Hormones should have kicked in nicely by the time a man reaches 18 but he must wait out his genetics as hormone alone are not responsible for the onset of beard grown. Beard transplants can be done when the young man is a bit older (over 26) if the beard has not grown in yet