There is a widely known demon called "Ba'al", who is one of the "seven princes of Hell". But honestly, it won't effect you if you don't think it will. So I don't think you have anything to worry about.
If you are very concerned, place some salt on the floor of your doorway and your window sill, and a mirror on the outside of your door. Burning sage is also another option, but don't play with fire if you don't know what you're doing, and it might not be okay with your parents.
The salt will ward away sprits that aren't welcome, as will the mirror will send back things that aren't welcome, either. Burning sage is the most common way to get rid of negative energy, or any other herb that makes you feel safe or have a personal connection with.
You mean your mind got a name of a demon and is real, may can be, because there are many demons that aren't are mentioned in any book or past, so if you think that this is a name of real demon then,call upon him, or else get rid by protective steps, and I think there's some reason that the name came in your mind, or its just your own mind that is making all the fuss, like the way one trusts any belief and may state that it's real.