Since we only know the title 'the real megan is missing story', it's difficult to say exactly who Megan is. She might be a young girl from a small town, or a woman living in a big city. Maybe she has a family, friends, and a job that are all affected by her disappearance.
Hard to say for sure. It might be based on a real incident that was then embellished or fictionalized to make it more engaging. Without further information, it's difficult to determine its authenticity completely.
I don't think it is. Many such stories are works of imagination, designed to capture the reader's attention and offer a unique narrative that isn't tied to real-life occurrences.