
I’ve answered a few similar questions to this in the past and I’m going to put the links here for you as I think you would benefit from reading them.
I do think it is really important to point out that the three examples you give in your question are very different things. A werewolf is a fantasy figure which does not exist in the real world. There are individuals who believe themselves to be werewolves but usually these people are suffering from delusion or the illness called lycanthropy. There are no human beings who can shapeshift into werewolves. (I’d be delighted to be proved wrong if anyone wants to question this! Lol)
Vampires are a slightly greyer area – there are certainly people who drink blood (though to the best of my knowledge this supplements rather than replaces a normal human diet) but the term vampire is more commonly used to refer to individuals who feed on the pain and negativity of others. This “psychic” vampirism isn’t in the least bit aspirational and I tend to view them as figures to be pitied rather than aspired to. Surrounding yourself with hate and negativity is a gloomy existence, don’t go there. Mind you drinking blood doesn’t sound much fun either. Stick with wine and chocolate.
A witch is not a supernatural being, nor a myth. A witch is just a person who happens to practise witchcraft. In that sense the witch is the least interesting of the three(!) but on a practical note it is also the easiest to turn into. In order to become a witch you simply start practising witchcraft (see the numerous questions on my site in reference to the born/made argument… Saying it of course is the easy bit. As with most things, it is easy to start the path but difficult to advance further without hard work, dedication and a spark or two of natural talent to guide you along. My advice to new witches is always to start with some hands on work combined with a bit of reading and see if it feels a good fit for you. Don’t focus on “being a witch” focus on practising witchcraft. If it feels right and you turn out to be good at it then you’re on the right path as a witch. If you haven’t got the time or inclination to put the work in then you’re probably not suited to being a witch. Think less about the title and more about what it is you actually want to do….
I need to become a witch
Should I refer to myself as a witch
Can you make me a witch?
How do you know you're a witch?
Image http://www.deviantart.com/art/I-m-A-Witch-66181271