merry meet. the quickest way to learn about the basics is to buy a book by a reputable source, Scott Cunningham and Raymond Buckland are two most people cite. There's also articles about the basics to help.
just side notes, as people will point it out like made, magic is not black and white, green and pink. in my opinion, when starting out, it does help colour coding so you can always know off the top of your head what colour candle works best with what spell, but magic isn't so easily categorized. magic is either positive or negative. i know what you mean by black magic, dark arts and stuff, there's a few people who study it here, and a coven you should join for more information on it.
your third eye is one of your chakra points associated with clairvoyance, there's articles up here to help you with that as well, but don't focus on it alone, your chakra's need to be balanced and working in harmony, one that's too open and another too closed will result in trouble. example, you have a fully open third eye but a closed root. you'll have headaches [third eye] and always feel nervous or uneasy. [root] this is an excellent article that's helped me:
good luck on your path, mail me if you need anything.