Well, in many fanfictions, the Avengers protect Peter by always having his back in battles. For example, Captain America might shield him from incoming attacks with his iconic shield. They also offer him guidance. Tony Stark could be constantly giving him advice on how to improve his suit and combat skills.
The Avengers are protective of Peter in fanfiction in various ways. Firstly, they keep him out of the most dangerous missions until he's fully trained. Thor might use his strength to fend off enemies that are too powerful for Peter. And Natasha would use her spy skills to gather intelligence to prevent any threats to Peter before they even happen. Secondly, they support him emotionally. Clint could be like an older brother figure, always there to listen to Peter's problems.
Because Peter is often portrayed as a young and inexperienced hero in fanfiction. He's like a little brother to the Avengers, so they feel a sense of responsibility to protect him.
One good example could be a fanfic where the Avengers shield Peter from a powerful villain who has a vendetta against him. They form a protective perimeter around him during a battle, with Thor using his lightning to create a barrier and Iron Man's suit systems on high alert for any incoming threats.
The protectiveness aspect is appealing because it shows the family - like bond within the Avengers. Peter is often seen as the youngest and most vulnerable, so when the Avengers protect him, it's like a family looking out for their own. It also adds an element of safety and security to Peter's character, which fans like.
In some fanfics, Peter might be exposed to a dangerous new technology. The Avengers, led by Bruce Banner, use their scientific knowledge to protect Peter. They analyze the technology and find ways to counter its effects on Peter. Natasha Romanoff also uses her espionage skills to track down those who are behind the threat. The Avengers' diverse skills are all utilized to keep Peter out of harm's way, which is a common and great theme in 'Avengers Protective of Peter' fanfics.
Peter might always keep an eye on Lucy during battles in fanfiction. For example, he would position himself between her and any approaching enemies. He would also be quick to defend her if anyone questioned her actions or motives in the Narnia - related events.
Peter is likely to be in awe. He might be a bit nervous at first, but also extremely excited. He has looked up to the Avengers for a long time, so meeting them would be like a dream come true. He would probably be stuttering a bit as he tries to introduce himself and show his respect.
One way is by getting involved in Peter's school life in a more official capacity. Maybe they could arrange for some anti - bullying seminars at the school. Natasha could also train Peter in stealth and evasion techniques so that he can avoid the bullies more easily. Thor could even offer to be Peter's bodyguard for a while, at least until the bullying situation is resolved.
Tony Stark might use his quick wit and technology. He could immediately scan Peter to make sure there's no physical danger causing the hyperventilation. Then he'd probably crack a joke to try and calm Peter down, like 'Kid, you breathe any faster and you'll fly away like a human jetpack.'
Darcy could also be a bit annoyed at times. She's a smart and capable woman. So when the Avengers are overly protective, like not allowing her to go to a certain place for her research because it's 'too dangerous', she might try to argue her case. However, deep down she knows they mean well and it's their way of showing they care.
In such fanfictions, their relationship is often depicted as very deep and complex. Peter is like a guardian to Neal. For example, when Neal is in danger, Peter will use all his resources to protect him. It's like a father - son or an older - brother - younger - brother kind of relationship.