Nikhil, my advice is to start here:

https://gointothestory.blcklst.com/test-your-story-concept-d6d7e0159b9b

It's critical to land on that last point: What is your emotional resonance with the story? That almost always boils down to the characters. What's your connection to them? If you *do* have a connection, that should lead you into the story-development process ... which at first is really about character development.

Follow the characters, especially your Protagonist. Get curious. Ask questions about and to them. That's the best way to start the process after locking onto a story concept.

Good luck!