The main characters are clearly Godric and Sookie. Godric is the vampire who turns Sookie into a vampire. Sookie is the one who undergoes this transformation. There may also be other supporting characters from the original story where Sookie comes from, like her friends or family members who will be affected by her new vampire status.
Godric and Sookie are the central characters. Godric, as an experienced vampire, has his own motives for making Sookie a vampire. Sookie, on the other hand, is a complex character. Her personality and her special abilities (if she had any before becoming a vampire) will play a role in how she adapts to her new life. There could also be other vampires in the story who interact with Godric and Sookie, either as friends or foes.