I'm sorry, I'm not very familiar with the specific 'ajab prem ki ghazab kahani'. It might be a relatively niche or regional story. You could try looking for it in local libraries or cultural heritage centers.
Since I don't know the specific story, I can't say for sure what the main characters are. But usually in a love story, there would be a male and a female lead who are at the center of the story.
I'm not very familiar with this specific 'ajab prem ki ghazab kahani love story'. It might be a unique and interesting love story from a particular culture or region. Maybe it involves some extraordinary elements in the relationship between the two lovers that make it 'ajab' (strange or amazing) and 'ghazab' (astonishing).
I'm not sure specifically who 'Ajab Singh' is without more context. There could be many people with this name. Maybe he is a local hero in a particular community, or perhaps an individual known in a specific field or family story.
The Panchtantra is a collection of ancient Indian fables. These Hindi moral stories are full of wisdom. One common moral is about the importance of friendship. For example, in many stories, characters who help their friends in tough times are rewarded. It teaches us that true friends are there for each other through thick and thin.