His best friend Ned could help. Ned is smart and good with technology, so he might assist Peter in finding the right components for the suit or in programming any new features.
Maybe Aunt May could play a role. She might not be a tech expert, but she could offer moral support and some practical advice on things like making sure the suit is comfortable enough for Peter to move around in easily.
In some fanfiction ideas, another superhero like Daredevil could help. Daredevil has his own experience with making and using his unique gear. He could give Peter some tips on how to make the suit more stealthy and better for hand - to - hand combat situations.
Well, perhaps Peter decides to make his suit because he wants to add some unique features to it. Maybe he's tired of the standard design. He could start by gathering special materials, like some super - durable fabric from a far - off planet. Then, he spends hours in his workshop, carefully stitching and adjusting every detail to make it fit perfectly and also be more functional in his superhero activities.
He will surely meet the Black Panther. It's Wakanda after all.
Maybe Pepper Potts could find out what Tony has done and rescue Peter. She might be able to talk some sense into Tony and make him release Peter.
Maybe some supervillains who were enemies of Tony. They see Peter as a continuation of Tony's legacy and want to stop him at all costs. They might target Peter to get revenge on Tony, even though he's passed away.
Peter might be initially suspicious. He's not always the most trusting character. He could wonder what Stiles really wants or if there's some kind of ulterior motive behind Stiles' request for help.
Maybe a new student who has some sort of special ability or knowledge that allows them to figure out Peter's secret identity. Or it could be a teacher who stumbles upon some clues accidentally.
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.
The plot could start with Tony noticing Peter's potential but also his limitations with his current gear. So, he decides to make Peter an Iron Suit. Peter is initially in awe of the new suit and has to learn how to use all its functions. There could be a scene where he accidentally activates a wrong feature and gets into a bit of trouble.
His best friend could be a main character. This friend might be the one who tries to understand why Peter did it and be there for him during his recovery if he survives. Maybe the friend was the only one who knew Peter was struggling before the jump.
Pepper Potts might appear. She could play a role in helping Tony take care of Peter, like making sure he has a proper diet and a comfortable living space in the Stark Tower. She might also be a maternal figure to Peter, giving him advice on relationships and growing up.