how can i learn how to cast spells?
well reading books and articles would be a good idea. you should learn 'the basics' but for spells, focus on meditating to clear your mind, charging/grounding energy, colour association, some basic herbs, and circle casting among other things.
how can i learn about magick?
again, books and articles. magic(k) is energy found all around us in nature, it cannot defy nature, so spells to change someone or something into someone or something else can't be done, along with levitation, time travel, flying, invisibility, and the like can't be done with magic because it goes against nature. spells for healing, love, luck, curses, and so on can be worked.
how can i learn something from this website?
read articles, ask questions on the forums, study spells [though double check with people first, there's some fluffy spells] join a coven, or ask people for help. there's a ranking system, though slightly flawed, it'll help you figure out who you should listen to, people with no ranking are usually new or fluffy, the system goes fluffy, beginner, novice, knowledgeable, adept. keep in mind most knowledgeable are mods and i think all adept are admin, some have spare time to help newcomers, but they're usually very busy.
is there any coven for beginners like me?
almost every coven is designed to teach people, some are for more advanced, but if you read the description you can figure out which coven teaching what you wish to learn as well as basics for newcomers. the one most people go to is Spellcasters, but if you want to learn, try finding a coven that actually teaches people.