I'm not sure specifically about this 'girl on the train hindi story' without more context. It could be about a girl's journey on a train, perhaps her experiences, the people she meets, or some sort of adventure that takes place during the train ride in a Hindi - speaking setting.
As I don't know the story, I can't say for sure. But probably the girl herself is a main character. There might also be other passengers, the train conductor or some people she meets at the stations.
Most likely, the main character is the girl. In stories that are named in such a way, the named entity is usually the one around whom the plot revolves. In this case, it's the girl on the train. She could be of any age, from a young girl to a young woman, and her actions, decisions, and experiences would be what drives the story forward in the context of the train journey.
To train in Hindi storytelling, first, listen to lots of Hindi stories. You can find them on platforms like YouTube or Storytel. Notice how the narrators use intonation and expressions. Then, start with simple stories and practice retelling them in your own words. Try to use the Hindi you've learned so far.
A good plot could be about a young boy's journey on a train. He meets an old wise man who tells him stories about the history and culture of different places the train passes through. This way, the boy not only has an interesting journey but also gains knowledge.
The 'The Girl on the Train' is a thriller story. It mainly follows the perspective of a woman who takes the train daily. She becomes involved in a mystery when she witnesses something strange from the train window. As she tries to figure out what she saw, she gets entangled in a web of lies, secrets, and danger.