One plot idea could be that the Avengers discover Spiderman's identity during a mission when his mask gets damaged. Then they have to protect his secret from villains who are also after it.
Iron Man might be protective. He'd probably see Spiderman as a young protege and would want to keep his identity safe using all his tech resources.
One idea could be that Spiderman discovers a new threat in his neighborhood which turns out to be linked to a much larger plot involving the Avengers. So he has to convince the Avengers to take him seriously and work together to stop it.
Well, a cool plot could involve Spider - Man's identity being revealed to the public and the Avengers having to protect him from various villains who see this as an opportunity to take him out. Or perhaps a situation where an old enemy of the Avengers teams up with one of Spider - Man's foes, forcing the two groups to work together more closely than ever. Spider - Man could also introduce some new tech or fighting styles to the Avengers during their joint adventures.
A plot could involve Spiderman accidentally getting caught in an Avengers - level battle right in his neighborhood. He then has to prove himself to the Avengers while also protecting his home and friends. Maybe he discovers a connection between the villain in the battle and the local crime in his area that he's been trying to stop in 'Homecoming'.
One idea could be that Spiderman 2099 has to team up with a group of rebels from a future dystopia to take down a powerful corporation that controls the city. They might face advanced technology and dangerous enforcers.
Another idea is a time - travel fanfiction. Spider - Man could be sent back in time to when his Uncle Ben was still alive. He would have the chance to prevent his uncle's death, but he'd also have to deal with the consequences of changing the timeline, like how it might affect his own development as a hero.
A story could be set in a future where the worlds of Marvel and DC have merged. Spiderman and Starfire are part of a new superhero team. They have to deal with the cultural differences between their two groups of heroes as well as face off against new villains created by the merger of the two universes.
One idea could be exploring what would happen if Spider - Man had to team up with a villain to stop a greater threat. For example, partnering with Doctor Octopus to take on an alien invasion.
One idea could be that Spider - Man has to face a new villain who has the power to manipulate his darkest fears and turn them into reality. Another could be a version where Spider - Man is wrongly accused of a major crime and has to clear his name while also dealing with the city turning against him.
A cool plot could be that there is a glitch in the game world that starts causing real - world disasters. Spiderman has to figure out how to fix the glitch by going deeper into the game code, all while still dealing with his regular villains.