Yes, all the Pagan Gods are real. You need your astral sight open to see him, and your clauraudience ability functioning to hear him. Please look at the meditations page under the Joy of Satan page (satanisgod.org).
To communicate with him now, you can meditate upon his sigil and pray to him. Responses will come in a variety of methods, such as seeing an abundance of the 666, 88, 13, etc. You may have dreams about him or items related to him, or you may feel a comforting energy after praying.
If you are questioning his existence and want to clarify this, I would suggest praying through his sigil and asking him for a sign of his existence.