Probably my favorite set of stories is by qntm, who writes lots of short fiction you can check out at his site. He wrote There Is No Antimemetics Division, which I think is best described by the intro he wrote for it:

An antimeme is an idea with self-censoring properties; an idea which, by its intrinsic nature, discourages or prevents people from spreading it.

Antimemes are real. Think of any piece of information which you wouldn’t share with anybody, like passwords, taboos and dirty secrets. Or any piece of information which would be difficult to share even if you tried: complex equations, very boring passages of text, large blocks of random numbers, and dreams…

But anomalous antimemes are another matter entirely. How do you contain something you can’t record or remember? How do you fight a war against an enemy with effortless, perfect camouflage, when you can never even know that you’re at war?

Welcome to the Antimemetics Division.

No, this is not your first day.

There’s a lot of other good entries too. They generally take the form of a wiki entry at https://scp-wiki.wikidot.com/, as a classified file describing some anomalous thing or event. They have a shared canon but only loosely, individual stories can conflict with one another. Here’s a couple good ones:

• https://scp-wiki.wikidot.com/scp-173 - The original. No picture because the creator of the picture didn’t like being used for SCP, but you can find it online
• https://scp-wiki.wikidot.com/scp-2521 - An anomaly that covets any written information about itself
• https://scp-wiki.wikidot.com/scp-3008 - An anomalous IKEA, got turned into a video game
• https://scp-wiki.wikidot.com/scp-j - Joke SCP

I’ll post over in !scp@lemmy.world too, to see what other people recommend for getting into it