For a character analysis paper on the story "Araby" by Joyce, I am concerned about how to write a thesis based on the main character.
We really could use more information on what you've noticed and researched about the character/narrator in Joyce's "Araby." I'll try to give you a little more information that might help.
The story suggests blindness and paralysis. At the story's heart is illusion. Check out the description of the street at the beginning of the story and the reference to it being blind, and other references to blindness. Illusion is seeing in a false way. The boy thinks there's something special about his "relationship" with Mangan's sister. Of course, it's not really a relationship at all. She hardly knows he exists.
When he sees the bazaar in person and everything is closed and even what is there for sale is not worth buying; and when he overhears the trivial conversation of the workers, he realizes how silly he's been and how trivial he's been and how what he saw as special was really an illusion.
His epiphany is an awakening, a realization about the truth of what he's been so obsessed about.
What you do with your thesis, then, depends on what you want to center on.
For your thesis, I would focus on the epiphany of the main character. In the story, the boy has many misconceptions that he builds in his head. He fantasizes about a girl, whose first name he apparently does not even know. The age difference and maturity of he and the girl is greater than he initially realizes. However, she offers hope and an escape from his drab existence.
Later when he goes to the bazaar, he has a moment of realization that puts his fantasies into perspective. Focus on building a statement that expresses his transition from the beginning of the story to his changed character at the end.