Witches

If someone could explain the white witch phenomenon to me i'd be very grateful, I'm interested to see if their magic actually works. I'd also like to know what happened to the dark witches, or if there are any local warlocks. When I was about 7 I went for a walk on the forest and found some rather intriguing looking fire circles so I may start camping out in the woods with my dad's night vision goggles (he bought them for badger watching) to try and see what my local coven is up to. They advertise for more members in the village bakery, but i'm not totally convinced I'm that magical at this point in my life, and do you have to go already convinced of your magical ability? What happens if you go to a coven and you don't know any spells, or know how to make them up? I think ill start tying string to objects and pretending to levitate them. Also a lot of the people in the coven have white witch bumper stickers on their cars which kind of ruins the surprise, however the fact that they give away their identity as a witch says to me that they're not up to anything too sinister because it would be too easy to track them down. How I love rural England.