You cannot turn into a vampire as vampires do not exist.
The whole idea of the vampire was based on Medieval misunderstandings about the normal changes a human body goes through after death. Such creatures were dreaded and feared up until the 1980's when there were a series of books, some movies, and a role-playing game that made vampires appear cool and sexy. But the fact remains that they are creatures of the imagination and fantasy. They do not exist so you cannot turn into one.
Furthermore, magic cannot change you into anything other than the person you already are. You cannot become any other sort of creature no matter how many spells you cast.