Most people who claim to be Satanists are still openly terrified of the concept of the devil which utterly defeats the purpose of the name, it was simply an edgy LARP from day one.
Even if they did actually worship a demon or big S they'd have no actual rites or any information beyond 'be really edgy' or 'do church but swap usual terms for Satan'. Comically I've seen more potluck style meetings for these alleged Satanists, so I guess they just like the fellowship part of Christianity without the faith.