Spending some time with the suggested essays will steer you in the right direction.
Self taught? Not exactly. Self discovered is more like it.
There are no requirements to observe any holidays, no requirements to conduct rituals, no requirements to meet in groups, on and on.
A person sees themselves as a Satanist not because they adopt a code or behavior, but on account that they are already, by nature, living and comporting themselves as such. They see themselves reflected in the pages of The Satanic Bible. Hence the phrase "Satanists are not made, they are born."
Those who read The Satanic Bible and say "I think I'll try this out" are looking for an identity, and seldom last long around us, and move on to the next suit to wear.
If you find and individual(s) who believe in an actual devil, who advocate drug use, who talk about animal sacrifices (let alone babies), that creature is a devil worshiper, someone who believes the Christian mythos involving the devil and what he supposedly does. There is nothing in The Satanic Bible that would lead anyone to conclude any of the above mentioned subjects have to do anything with Satanism.
Satanists pretty much keep to themselves. Here and there, especially amongst the younger ones in the service, there might be one or two who brag about it, and soon learn the error of doing that. Most Satanists are not open about their religion or affiliation.
Responsibility to the responsible. That is a major tenet. When you read The Satanic Bible you will see that it is straight forward, and not really given to interpretation.
I'd keep an eye out for those you described in your post. From your description they seem to be troublemakers.
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