He might meet his old friends from before he left Earth. People he used to hang out with, like schoolmates or neighbors. They could be shocked to see him after all this time and how much he has changed.
Another theme is friendship or romance. Many fanfics explore the relationship between the female character and Peter Quill. It could start as a friendship based on mutual respect for each other's skills, and then develop into something more romantic as they share more experiences.
There could be a fanfiction where a female version of Peter Quill exists in an alternate universe. She has all of his charm and bravado but with a unique feminine twist. This fanfiction could explore how she rises to become a leader in her own right within the Ravagers, defying the expectations of those around her.
You can start by looking on popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created works, and you can use the search function to specifically look for female Peter Quill fanfiction. Just type in relevant keywords like 'female Peter Quill' and browse through the results.
Peter Quill's origin story begins on Earth. He had a difficult childhood as his mother passed away when he was young. After being abducted by Ravagers, he was thrown into a world full of strange and diverse alien races. This experience shaped him into the adventurous and somewhat roguish Star - Lord we know. He learned to survive in the harsh and unforgiving space environment, using his wits and the few Earth - based items he had, like his Walkman, which also held sentimental value as it was related to his mother.
Peter Quill and Mantis aren't siblings in the comic world. There's no established connection of that kind. They have their own unique roles and arcs that don't involve being related by blood.