That ability to start new covens has been locked on Spells of Magic for the time being and new covens are not to be created at the moment.
There are plenty of already existing covens on this site that teach and specialize in a great deal of magic fields.
If you wish to join a coven to learn, feel free to browse the coven listings page (Groups tab) where each existing coven is listed appearing next to its picture/logo.
If you are concerned about what they teach or include simply view their homepages (by clicking on the coven's title) and you may possibly find the information you seek. If your concerns are not answered by viewing their homepage, it usually works to simply email the coven leaders or if the coven has council members they may sometimes be able to help as well.
Remember, new coven applications are closed and new covens are not as of right now, able to be created.