Perhaps Peter meets Thor when the Avengers are having a recruitment drive. Thor is initially skeptical of this young 'Spider - boy' as he might call him. But as they train together, Peter's agility and Thor's strength complement each other. They end up on a mission together where Peter has to use his webs to save Thor from a fall, and Thor in turn uses his lightning to power up Peter's suit for a short time. This experience makes them respect each other more and they start to bond.
One possible plot could be that Peter, being his curious self from Queens, stumbles upon Thor in a strange situation. Maybe Thor is trying to adapt to life on Earth without his powers for a while. Peter, with his quick thinking and scientific knowledge, tries to help Thor figure out what's wrong. Along the way, they form an unlikely friendship, with Peter constantly asking Thor about Asgard and Thor learning about the modern world from Peter.
Maybe in the fanfiction, MCU Peter is on a mission when he accidentally stumbles into a portal and ends up in the world of another Peter. They start comparing their lives, like how different their love interests are. MCU Peter could learn some old - school web - slinging techniques from the other Peter, and they end up having to fight a villain that threatens both of their worlds, leading to a great team - up.
In a 'Thor meets Wonder Woman' fanfiction, perhaps they meet in a neutral realm. Thor is intrigued by Wonder Woman's connection to the Greek gods while she is curious about his Asgardian heritage. They get involved in a tournament of sorts where they have to team up against other powerful beings. During this time, they share stories of their heroic deeds. Thor tells her about his battles against the Frost Giants and Wonder Woman shares her tales of protecting the world from Ares. By the end of the tournament, they exchange gifts - Thor gives her a small Asgardian charm and she gives him a piece of Amazonian armor.
Peter's personality is very much based on his youth and inexperience but also his eagerness to prove himself. Thor has the confidence of a god and a long history of battles. At first, their clash might be due to Thor not taking Peter seriously. However, as they get to know each other, their personalities blend. Peter's quick thinking and adaptability can be useful to Thor, who is sometimes set in his Asgardian ways. And Thor's leadership and courage can inspire Peter to be a better hero.
A plot could involve Peter's identity being at risk and Daredevil helping him keep it a secret. Since Daredevil is so good at operating in the shadows, he could teach Peter some new ways to move around the city without being detected. They could also have a conflict about their different approaches to justice. Peter is more about saving everyone, while Daredevil has a more 'punish the guilty' attitude at times.
Well, perhaps Thor and Richard could meet in a modern city. Thor is on a mission to retrieve a powerful artifact that has been smuggled into the human world. Richard, who is an expert in ancient relics, unknowingly has the key to finding this artifact. Their meeting could start with Thor saving Richard from some thugs who are after the same artifact. And then they team up to find the item before it falls into the wrong hands.
In a 'Peter Pan meets Tinkerbell' fanfiction, there could be a plot where Tinkerbell accidentally gets cursed by a dark magic. Peter Pan then has to search all over Neverland and beyond to find a cure. Along the way, he meets different characters from other stories who have heard of similar curses. Meanwhile, Tinkerbell is struggling with the effects of the curse, which start to change her personality. This could lead to a very emotional and action - filled story as Peter Pan races against time to save his friend.
Well, perhaps Jack Frost accidentally enters Neverland while chasing a particularly strong winter wind. Peter Pan mistakes him for a new kind of fairy at first. Then they start to compete in various things, like who can fly faster (Jack using his ice - made wings and Peter with his pixie dust). But as they get to know each other, they realize they have a common enemy in Captain Hook, who wants to use Jack's ice powers to freeze the mermaids' lagoon and catch them easily. So they have to work together to stop Hook.
In some fanfictions, they might team up to fight a new villain. Picture them combining their powers and skills. Peter Parker's acrobatic skills and spider - sense along with the other Peter's unique abilities could make for an epic showdown against a powerful enemy.
One possible plot could be that Peter Parker, while on a school trip or some scientific research in space (maybe with Stark tech), accidentally stumbles upon Peter Quill and the Guardians of the Galaxy. They initially have a bit of a misunderstanding as their ways of doing things are quite different. Parker is used to the more down - to - earth (literally) problems in New York, while Quill is dealing with intergalactic threats. But they soon realize they can learn from each other. Parker could teach Quill about the latest Earth - based technology, and Quill could show Parker the wonders of the galaxy.
One possible plot could be that Peter discovers his true parentage as Thor's son later in life. This revelation could change his entire perspective and lead him to Asgard to learn about his heritage.