Satan can only get angry if you intend to offend him or attack him, his Gods/Demons or his people (fellow Satanists). If you are a normal Spiritual Satanist and not one of Satan's enemies who intend to do those things then you don't have to worry about him getting angry at you.
If you have a fearful thought or a voice telling you that Satan is angry is just your programmed fear and guilt from Christianity, don't take it seriously.