The era of the professional Pagan writer is a new one indeed, and as it stands now, there are very few organized or formal resources for us where we can learn of new markets, get feedback on our work, or contact other writers for collaborative/supportive purposes.
Come here and add your voice. Take some time to share resources you've heard of. Critique the editing techniques of various publications. Had a good experience with a magazine? Had a bad experience? Let us know so we can either seek out or avoid that particular publisher. Let us know when you've got an article coming out. Swap research. Fish for collaborators. Post works-in-progress for suggestions and commentary. And just take some time to share your experience of the writing process in a community where there are others who will understand.
No age limits. No rules beyond "play nice with one another". Hopefully, in time, this can grow into a valuable source of information and support.