He might make friends with Sirius Black right away. In fanfiction, they could start exploring the secret passages of Hogwarts early on. Maybe they'd have a run - in with Filch while trying to find the rumored hidden rooms.
Snape could be one of his enemies. In fanfiction, Snape might already be jealous of James' popularity and natural talent in magic. So, there could be a lot of tension between them, with Snape constantly trying to one - up James in classes.
One common theme is the transformation of James. He starts as a bit of a bully but then changes to be a better person for Lily. Another theme is the friendship group. Their friends, like the Marauders, play important roles in their relationship. For example, Sirius might encourage James to pursue Lily or Remus gives advice on how to understand her better.
One possible plot could be that James Albus and Lily Potter are facing a new mystery at Hogwarts. Maybe they discover a hidden chamber that no one has found before and inside it are secrets about their family's past at Hogwarts. They then have to figure out how to deal with these revelations while also keeping up with their studies and normal Hogwarts life.
The main characters are obviously James Albus and Lily Potter. They are likely to be the central focus of the fanfiction, with their adventures and experiences at Hogwarts being the main storyline.
One great fanfiction is 'The Marauders' Era: Lily and James'. It beautifully portrays their relationship during their Hogwarts days. It shows how James matured from a bit of a troublemaker to someone worthy of Lily's love. The author does a wonderful job of depicting the Hogwarts setting and the interactions between the characters.
Perhaps in this fanfiction, the plot focuses on Harry's relationships during his last year. He could be trying to mend some broken friendships or develop new ones. There might also be a romantic sub - plot where Harry finally figures out his true feelings for Ginny and they face some challenges together. Meanwhile, there could be a mystery surrounding an old Hogwarts secret that is uncovered during their last year, leading to an adventure that involves all the students.
Well, he'd probably be more of a legacy student. He might be treated with even more respect or envy from the start. And he could have a different group of friends. Instead of Ron and Hermione, he might be closer to his brother's old gang, like Sirius and Remus, from the very beginning at Hogwarts.
A possible plotline could be that Hogwarts itself becomes a sort of magical battleground earlier than expected. The Death Eaters try to take over the school completely, and the students and remaining teachers have to fight back in a sort of guerilla warfare within the castle walls. This would change the whole dynamic of the seventh year, with classes being interrupted and students having to use their magic in real - life combat situations.