A story's exposition introduces readers to the main characters and setting. In this book, the main protagonist is Jerry. He is beginning his freshman year at Trinity, an all-boys high school. We are also introduced to The Vigils and Brother Leon.
The conflict and subsequent rising action involve The Vigils giving Jerry an assignment to not sell Brother Leon's chocolates. Jerry is actually okay with that assignment; however, he'd rather sell the candy than be on Brother Leon's bad side. The tension rises, as Brother Leon is shocked that anybody wouldn't do his bidding, but the action continues to escalate when Jerry refuses to start selling after his Vigil assignment is completed.
I think that individual readers could defend two different moments as the climax. Interestingly, it is essentially the same event. Jerry gets beaten to a pulp. If you choose the first time this happens, then the final fight when Jerry attends the raffle and Brother Eugene turns off the lights would be part of the falling action. This would be my recommendation.
The final resolution is a major downer. We see Jerry wondering if any of it was worth it, and we see Obie and Archie walk off into the night. They have emerged completely unpunished, and this gives readers the impression that this way of life at Trinity is likely to continue.
Exposition (characters and setting): The story takes place at Trinity, an all-boys school somewhere in New England, and at Jerry's home. The time period is roughly the 1970s, identifiable through a reference to a song from the 70s. The main characters are Jerry, Archie, Brother Leon, Emile, and Roland.
Conflict: Jerry refuses to sell chocolates at the school chocolate sale.
Rising Action: The Vigil gang, a group of bullies, gives "assignments" to students. One example is when Goober is told to unscrew all the furniture in Brother Leon's class so that it falls apart during class. Various students view Jerry as an enemy because he refuses to sell chocolates. He is bullied and harassed.
Climax: This occurs at the assembly where Jerry fights Emile to get back at everyone who has done something to him for his refusal to sell the chocolates.
Falling Action: The fight is stopped when a teacher turns off the power to the field.
Resolution: An injured Jerry decides that there was no way to win and that he should have complied.
Exposition: Jerry's refusal to sell chocolates at the school chocolate sale.
Rising Action: Jerry's refusal after the first ten days and the Vigils' subsequent punishment of that choice.
Climax: The assembly at which Jerry fights Emile Janza for the chance to get back at everyone who has punished him for his decision not to sell the chocolates.
Falling Action: The ending of the boxing match and Jerry's subsequent realization that it is not worth it to disturb the universe.
Resolution: Jerry has a broken jaw and possibly some internal injuries. As he is waiting for the ambulance he tells his only friend, The Goober, not to disturb the universe—that it is not worth it. The book ends as Archie displays no remorse for the past, and Jerry no hope for the future.