Okay, so there's a lot of things going on so let me clear things up.
Jack and Elsa grew up together because of their parents. As they grew older they bonded more. Jack grew more and more popular in middle school but his friendship with Elsa stayed strong. There, they met the others (the other mains). High School came and the two wee separated. They didn't have any classes together. Jack has been playing soccer since middle school and so had Elsa. They were on different teams though (girls team and boys team) so they still didn't see each other often. During sophomore year Elsa and Luke had the same classes and since they both liked soccer, they found interest in each and started to date.
They stayed together all year going into Junior year. They broke up when first quarter ended but remained friends. The next year was/is Senior year and Jack and Elsa for the first time in Highschool, had classes together. Now that they have the same classes, they can now be best friends again. They find each other very attractive seeing as they both passed pubertyXD. (<lol ignore me). Anyways, a lot has changed and their personalities have too. This year is special since Jack, Elsa, Anna, Hiccup, Merida, Rapunzel and Flynn all have some classes together (not all at once but they see each other at least once). So like I said, their personalities have changed so Elsa and Jack are kind of meeting each other for the first time. Trevor and Elsa had classes together Freshman and Sophomore year and they just became closer. Trevor is gay but there is no hate, if you don't like it then don't read this book because it's rude and judge mental and it really does hurt people's feelings. Trevor lind of became one of Elsa's best GIRL friend but he's a guy so yeah. So then there's Hans. He's a transfer student and moved to the school on Junior year. Jack, being the good guy he is, decided to give him a chance and that's how him and Hans become 'friends'. As you already know, Jack introduced Hans to Elsa and then the fiasco started.
Also, if you didn't catch up on it, people Jack's friends with (the popular ones) are kind to the shy ones. There are rude ones too (Hans for example). Rude ones will show up in the story later on so just know who the enemies are because not all populars are like that.
I really hope this cleared things up but then again, I have a rep for making things worse. So yeah, thanks for reading please vote and comment and I'll post the next chapter...Whenever. idk.
~v