How someone get into deep/dark web shits? (I refer to things like red rooms, snuff and all that stuff)

Relax, im not one of that stupid children that wants to be edgy. I want to be a writer and i have a good idea, in which i need this, u know, witouth getting too much deeper, just to do it realistic
-i will do a slow procces, not a specifically situation in which the mc suddenly gets involved, but any detail is useful to me-