Agiel is correct, you also probably mean "being able to cast spells". For this you have to make your spiritual/magickal energy stronger, this is done by energy control. I think if it's strong it means you have a strong Aura.
we are all magick. magick is a natural energy that creates a natural change. not everyone who believes in magick casts spells however so you might wish to specify if you're more interested in spell casting [though you should learn how magick works]
you can 'have magick' by practicing a few energy techniques to help you feel the natural flow of energy so you become more aware of the energy. look into grounding and charging energy as well as psi balls.
grounding and centering: http://www.spellsofmagic.com/read_posts.html?post=598114
The Basics: http://www.spellsofmagic.com/read_post.html?post=483942