What main changes does Paul Fisher go through?

In Edward Bloor's novel Tangerine, Paul Fisher is the main character and narrator. He is also a dynamic character. The main change he goes through is finding his identity in the shadow of his older brother, Erik. He also finds the courage to confront Erik at the end of the novel, which no one else in his life has been able to do.
Paul is dealing with a move from Houston, Texas to Florida. He has a pragmatic mother and a nearly absent father. His father focuses most of his energy on his dreams of football glory for his oldest son, Erik. Paul also has a disability, he is vision impaired, and has fuzzy memories of the accident that caused this.
Paul has confidence in his abilities in soccer but gets kicked off the team at Lake Windsor Middle School because he is on an IEP, or individualized education plan, and the school can't insure him as a player. Due to a sinkhole which destroys most of the portable classrooms at Lake Windsor Middle, Paul is able to transfer to Tangerine Middle School. He convinces his mother to not transfer the IEP so he can play soccer. Through this experience, he learns a lot about being a team player and a good friend. He gains confidence as well as friends. His changes run parallel to his older brother Erik, a static character, who continues the same pattern of self-promotion and self-absorption he has maintained all his life.
Paul sees the injustice that his brother Erik is responsible for in the death of his friend's relative, Luis. He also sees Erik lie and manipulate the situation so that he won't face consequences. At the same time, fragments of memories of the accident that damaged his eyesight come to him. He eventually puts the pieces together and discovers that Erik's cruelty is responsible for his vision impairment as well as Luis's death. He confronts his parents and Erik, and as a result, justice is finally served. At the beginning of the novel, Paul lives in the wake of Erik's shadow. He feels inferior to Erik, and as a result, he struggles to find his worth. At Tangerine Middle School, he finds a group of friends who help him grow in confidence. He also grows in self-worth, realizing he has many valuable things to contribute, both on and off the field. Even though he goes through many struggles in the book, he realizes that those struggles have made him stronger. In contrast, no one ever allowed Erik to go through struggles, and it made him into a cruel and careless individual. Paul accepts the consequences to his actions but also gains the perspective that it is not the end of the world, but only a temporary, light affliction.

Paul Fisher goes through a variety of changes. He is a dynamic character who grows and develops throughout the book.
At the beginning of Tangerine, Paul was  a weak pushover who allows his brother to mercilessly bully him. He had low self-esteem due to Erik’s relentless taunting. However, at the end of Tangerine, he became an empowered and decisive young man with the power to  stand up for himself and his friends. These changes were primarily motivated by his move to Tangerine Middle School and his growing understanding of Erik's cruelty. 
 First of all, Paul's family moved to Tangerine from Houston. This major change should have allowed  Paul to begin anew, but his hopes for a self-reinvention were dashed by his parents’ focus on Erik’s burgeoning superstardom on the football team. It was a negative change, given that Tangerine held new dangers (muck fires and sink holes) and the same old problems as Houston; for example, Erik quickly got up to his old tricks and found new lackeys to torment Paul. Consequently, the first major change to positively impact Paul was his move to Tangerine Middle School, where he was able to make new friends, experience success on the soccer team, and gain the necessary confidence to confront Erik.
When Paul saw  Erik’s lackey, Arthur Bauer, demean his new Tangerine friends and fatally injure Luis Cruz, Paul underwent  a change of heart. He found himself no longer able to stomach Erik’s cruelty, and he joined his friends by attacking Erik and the football team at an awards ceremony. He also regained his memory of how he lost his sight back in Houston (Erik and one of his friends spray-painted his eyes.) Consequently, Paul gained both knowledge and power.