ok, i am sorry to tell you this, but you cannot change into a blood sucking dracula vampire. i am not saying that vampires are not real however, in the astral they are, and there are psi vampires, and yes, i'll even mention sanguine vampires, but if you've just watch Buffy, or Interview with a Vampire, or Twilight or something and want one to bite you and turn you into one, that cannot happen. you were born human, and nothing will change that, sad but true.
you could always look into blood magic, and incorporating vampires into you magic work. i've seen tons of vampire decks, alter cloths, incense holders, chalices, books, and even came across a wand once. i know hearing people say bad things and tell you you are wrong must hurt, but you can't silence people's opinions unfortunately, just like you can't silence facts. the fact is it can't happen. you could get someone to sharpen your canines teeth into fangs, wear contacts, eat rare meat and avoid garlic, but unless you were born a dracula vampire, you cannot change with or without magic. don't get upset, like i said, look into blood magic, try your hand at becoming a psi vampire, collect different tools with vampires in them. hope i helped a little, blessed be.
While I realize you included " P.S. if you say vampires don't exist I don't want to hear from you at all" I am, unfortunately, going to tell you just that. There is no spell which will turn you into a vampire, that is fantasy, and you do need to hear that so that you do not waste your endeavors or feel misguided about something. I think Neko did a good job of explaining it more in-depth, but there you have it.