start with basic energy training(feeling, controlling, reading, manipulation and just its use in its raw form, also learn to read and use its spectrum) and meditation, following link should be of some help.
After you are done with it start your study on spirits, angels, demons and other energy(spiritual) beings.
Then move on to cleansing, protection, binding and banishment spells, rituals and charms.
Do NOT STOP with energy training and meditation.
And finally you can start with attempts to contact beings on spiritual and/or astral plane just be sure to start small.
!!!BE SURE THAT SAFETY MEASURES ARE IN PLACE!!!