One example could be a story about a little girl who finds a lost puppy on her way to school. She takes it to the local vet, and they manage to find the owner. It's a simple yet heartwarming story.
First, think of a simple idea or event, like a cat getting stuck in a tree. Then, develop it by adding characters, like the kind neighbor who tries to rescue the cat. Finally, give it an ending, such as the cat being safely rescued.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.