Not having read 'the carnival children's story', it's hard to be certain. But it's likely that the main characters are kids. They could be a group of friends who go to the carnival together. There might also be an adult figure like a parent or a guardian who is part of the story, either as a supporting character or as someone who helps the children in their carnival - related adventures.
I don't know the story, so I can't say for sure. It could be a young couple in love, or a lonely person looking for something at the carnival.
Since we don't know the details of the 'fat man carnival story', it's hard to say for sure. But most likely the fat man himself is a main character. There could also be carnival workers, like the ticket seller, the ride operators or the food vendors who might be important characters in the story.
There could be a special performer, like a trapeze artist who has a tragic past. She might be haunted by something that happened in her previous life outside the carnival, and her story is intertwined with the overall mystery of the Dark Carnival. Her skills on the trapeze are not just for entertainment but also a way for her to escape, at least momentarily, from her inner demons.
Perhaps it's a little boy who has a special pet. The boy and his pet could be the main characters, going through various experiences like helping their neighbors or solving a mystery in their neighborhood.
There's Vignette Stonemoss, a faerie. And there's Rycroft Philostrate, a human inspector.
I'm not entirely sure as it depends on the specific version of the graphic novel, but often there's a protagonist who is an outsider drawn into the carnival.
Since I don't know this story specifically, it could be about children having adventures at a carnival. Maybe they discover some magic there, or meet interesting characters. It might also be about the friendships they form during the carnival.
There's Rycroft Philostrate, a human detective who is involved in the events around Carnival Row. And Vignette Stonemoss, a faerie. They are two of the main characters.
In the 'noah children's story', the main character is surely Noah. He is the one who gets the instructions from God to build the ark. His sons, Shem, Ham, and Japheth, are also main characters as they help Noah with the building and are part of the family that is saved. Noah's wife also plays a role. And the animals, which are numerous and diverse, are like a collective character. They represent the life that Noah was tasked to preserve.
I'm not sure as I don't know the 'jeremiah children's story'. It could be Jeremiah himself as a main character, and perhaps his friends or family members.