The movie starts out with a boy and his father as shepherds.
They see a dragon, go after the eggs for profit and the dad dies.
The dad dies and the son is sent off to a lord who owes his father a debt. The boy is supposed to be trained as a vassel or knight or something.
The lord has a daughter who tries to help teach the boy when her father doesn't.
The dragon returns and the lord and the daughter's prospective husband go hunt it. The boy goes out separately to hunt.
The boy kills the dragon