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.
Since I haven't experienced this 'ajab gazabb love story', I can't tell who the main characters are. But usually, in a love story, the main characters are the ones whose love story is being told. They could be ordinary people, or they might have some special qualities or circumstances that make their love story interesting. Maybe one is really kind - hearted and the other is very adventurous, and their different traits draw them together in this story.
The 'ajab gazabb love story' might be a story full of surprises and wonders in the realm of love. It could feature characters with distinct personalities who fall in love in an unexpected way. It may have elements like misunderstandings that they need to overcome, or perhaps it's a story of love against all odds, where the two lovers face various challenges but still hold on to their love for each other.