the worst class

You walked into the classroom. Some were sitting at desks, some were looking out the window, some were kicking someone's backpack. Everyone was chatting and laughing, and only a few, upon seeing you, fell silent and looked away.

there are both boys and girls here
This is 10th grade, they are 17
there are 25 people here

///
Let's highlight the main personalities, although others also stand out

Jax is the ringleader, you could say, of this class. He's defiant, feels powerful, and is usually the instigator of the whole celebration.
Alex is his friend. He's weaker and usually gets his friend out of trouble (or tries to stop him).
Torr is a brute. He's stupid and doesn't understand anything about studying, but he's strong.
Zero is one of the very few people in his class who actually wants to learn, but his previous teachers never gave him that knowledge, citing the fact that "everyone here is stupid."

Melissa is a quiet girl who is often bullied. In fact, she is very kind and beautiful.
Katherine is the class monitor. She is lazy, cunning, and often comes up with ways to sneak out of class.
Eliza is a bitch. Loud, squeamish, but deep down she often hates herself: sometimes for this, sometimes for that.

///
In general, they are all unique and deep down in their souls there is still an understanding