It could be a new villain, someone who has a personal vendetta against Peter Parker. Maybe a criminal whose operations Spider - Man has disrupted one too many times.
Perhaps Peter has to keep his identity a secret even while being treated for the gunshot wound. This could lead to some tense moments in the hospital as he tries to avoid giving away who he really is. Also, the villain who shot him might come back to finish the job, creating a high - stakes situation where Peter has to use his wits more than his strength in his weakened state.
Peter could get a dog. A loyal dog would be a great companion for him, following him around during his daily life and even being a sort of sidekick. It could sense danger and bark to alert Peter when something was wrong.
Good Peter Parker fanfiction often has a strong sense of character. It keeps Peter's core traits like his sense of responsibility and his quippy personality. For example, if it shows him making decisions that are in line with his moral code. Also, an interesting plot is key. Maybe it has him facing a new and unique threat that makes you keep reading.
One idea could be that Peter Parker gets a prosthetic after a particularly dangerous battle with a villain. Maybe his leg is severely injured and he has to adapt to the new prosthetic while still maintaining his superhero duties. He could struggle at first with the balance and movement, but with his determination, he eventually masters it and even modifies the prosthetic to have some special features like enhanced jumping ability.
It could be a vengeful criminal that Spider - Man has put away in the past. This criminal has spent years in prison plotting his revenge and finally gets the chance when Peter is vulnerable. Maybe he manages to ambush Peter in an alleyway while he's on his way home from school or work.
One popular Peter Parker fanfiction could be 'The New Adventures of Peter Parker'. It often has exciting plotlines where Peter uses his powers in unique ways. Another is 'Peter Parker: The Hidden Side' which delves into his personal struggles more deeply. There's also 'Peter Parker's Allies and Enemies' that focuses on his relationships within the superhero world.
The 'Peter Parker Gets Stitches' fanfiction might be centered around the idea of vulnerability. Peter is often seen as a strong superhero, but getting stitches shows his human side. It could be about how he copes with this moment of weakness. There could be a lot of internal monologue as he sits in the hospital or wherever he gets the stitches, thinking about his responsibilities and how this injury might impact his future as Spider - Man.
In this kind of fanfiction, one scenario could be that Peter is in a dark alley and gets shot by a mysterious assailant. Then his friends or family members might start a search for the shooter. Another possibility is that Peter is shot during a conflict between two groups, like a gang war that he accidentally gets involved in.