I can say spirits are real cause I had a real encounter, not a shadow, or orb but a real hand being drag down my back when I was alone in a room. I hear many things about the Ouija board, and some say it is real, and others not. I have been seeking the paranormal now for almost thirty years, from Ouija boards, and Tarot cards, and I have no doubt that things can happen the are hard to explain, but that is what science is trying to do. I don't feel you are dealing with a Demon at this point, yet it is always important to remember that just like in life people lie, and so do Spirits. Test the spirit to see if it's intent is bad, and this should not be hard to do. Keep a open mind, but always keep your guard up. I hope you and your friends enjoy your time with the Ouija.
Studier of the Paranormal, and it's practices for almost thirty years.