Start by studying the basics such as meditation, centering, grounding, energy manipulation and visualization.
These can be searched for in the search bar on the forums page.
The basics take time so it could be months or even a year or two before you cast your first spell.
Also research into what magic truly is and how it truly works so you know that you cannot change your dna in anyway or grow wings or teleport or create fire balls. If it seems illogical than it probably is.
Following up on basic's here's a few pointers on things that will help you more
For meditation http://psi.wikia.com/wiki/Meditation
That link contains helpful tips on different types of meditation also http://free-binaural-beats.com/product/creativity-focus/
That link leads you to a binural beat giving that a listen while trying to meditate may help if your one of those that have a hard time clearing your mind.
For energy manipulation the best skill to learn is the psi ball
That link will give you a good description on how to train to make one. Just don't attempt to make one on an empty stomach.
For Grounding http://psi.wikia.com/wiki/Grounding
And visualization http://psi.wikia.com/wiki/Visualization
Those links with all the detail in describing them help immensely with understanding what to do