Rey: Kind of a normal person. She likes astronomy class, but doesn't like the other classes. They're  boring. Her best friends are Poe and Finn. She's pretty popular though. Sophomore.

Finn: is the jock of the school. Loves sports, and is pretty good at them. His best friends are Poe and Rey. Sophomore.

Poe: The cool kid of the school. Everyone likes Poe. He's pretty popular, but spends alot of time with Rey and Finn. He has a small pet dog who's name is Beebee. Sophomore.

Kylo Ren: The bully of the school. He bullies all the kids and particularly hate the three best friends. His real name is Ben, but his "friends" and enemy's call him Kylo. (Rey calls him Ben to irritate him) a sophomore.

Leia Organa: A school teacher. Happens to teach astronomy, Rey's favorite class.

Han Solo: Leia's husband, the cool person who is always taking the kids to do fun stuff. He doesn't really have a job, but runs around town with his best friend, who's nickname is Chewbacca.

Hux: Kylo Rens rival. Also a bully, but less so than Kylo and more whiney. A Sophomore.

Snoke: The principle of the school, a ruthless principle who hates all the kids and is extremely unfair to them.

Beebee: A dog version of BB-8. He's peppy, silly, and always follows Poe. (check the pic above.)

Maz: The lunch lady. Runs the cafeteria, and some of the kids call her Mozzarella. The three best friends don't. They like her alot, but Finn is sometimes scared of her and her huge spectacle glasses.

Chewbacca: No one really knows what his real name is. He's just- Chewbacca. Anyways, his best friend is Han, and they're always together.

Luke: a teacher who joins into the book a little later. Rey loves him and so do Finn and Poe.

Nien Nunb: Also a teacher. He teaches Spanish. Talks funny and the kids like him.

Phasma: A freshman who's just as jerky as any bully you ever would find. She just thinks she's all that, and cuts her hair like a boy. Always wears silver and red. Comes in later.

Unkar Plutt: English teacher. Very fat. VERY. The kids call him Blobfish. He's kinda old. Always wears old timey hats.

Mr. "Admiral" Akbar: Teaches Math. Used to serve in the Vietnam War. Us always talking about the "Glory" Days, and the roaring 20's. He wasn't alive for them, but always talked about them.

Lor San Tekka: Grammar teacher. Gets sick alot. Very old. Poe likes him a lot.

If there are any characters I missed or you would like to be added from TFA, please recommend them!

Classes:
Spanish -Nien Nunb
English- Unkar Plutt
Astronomy- Leia Organa
Science- Luke Skywalker
Math- Admiral Akbar
History- None other than Snoke himself.
Grammar- Lor San Tekka
Lunchlady- Maz Kanata

Yeah that's basically all I got. If there is any other teachers, or classes you can think of, just let me know.