Maybe Peter was doing a science experiment in class and something went wrong, like a chemical explosion that injured him. The other students could be in shock and the teacher would have to quickly take action to get help.
His classmates would probably be very concerned. Some might immediately run to get the teacher or the school nurse. Others might gather around Peter, asking if he was okay and trying to comfort him.
Peter was playing football with his team. In a fierce tackle, he was pushed too hard and his ankle twisted in an unnatural way. The pain was immediate and intense. His teammates stopped the game and gathered around him. One of them, who had some first - aid knowledge, tried to immobilize his ankle. Then they carried him to the side of the field and called for his parents to come pick him up and take him to the doctor.
This situation in the fanfiction could also be a part of a bigger story arc. Wanda might be calling Peter as part of a plan to form a group within the school, like a secret club of students with special abilities. It could be the first step in bringing together a team that will later face a common enemy or solve a major mystery in the school. The call in class is just the catalyst for what's to come.
One possible plot could be that Peter is injured during a superfamily mission. Maybe he's trying to protect a younger member of the superfamily. The other members then have to step up and take care of him while also dealing with the threat that injured him in the first place.
Perhaps it's his best friend who has some juicy gossip to share. But it's really bad timing as he's in class. His friend might not be aware of his class schedule.
Peter would probably be shocked at first. I mean, getting a call from Deadpool in the middle of class is not an everyday occurrence. He might quickly look around to see if anyone noticed his phone ringing.
Well, it could be that Peter gets injured during a fight in class, perhaps with a bully. And his friends then have to deal with the situation while also trying to keep it from the teachers.