Author Gary Schmidt sets up the narrator right from the first lines of this pleasantly humorous and historically interesting story, The Wednesday Wars. The opening salvo lets the reader know that the person talking is also the person experiencing the situation in the story:
Of all the kids in the seventh grade at Camillo Junior High, there was one kid that Mrs. Baker hated with heat whiter than the sun.
And let me tell you, it wasn't for anything I'd done.
The personal pronouns (me, I) tell us that the one telling the story is also the one experiencing the story. We are amused and enlightened about the setting and the town's religious divides for three pages before we finally find out who this person with the personal pronoun identifiers is, but at last we meet him at roll call:
This left behind just the Presbyterians--of which there had been three, and now there was one.
I think Mrs. Baker suspected this when she came to my name on the class roll. ...,
"Holling Hoodhood," she said.
"Here." I raised my hand.
Mrs. Baker sat on the edge of her desk.
The story, therefore, is being told by the hero and the first-person narrator, Holling Hoodhood (Hoodhood is a name symbolizing how both the neighborhood cultures meet at Holling's house, "The Perfect House," "right smack in the middle of town").
Holling is telling the story while still a boy from the near future since there are no tell-tale detached adult comments amplifying the narrative, such as you will find in Scout's narrative in To Kill a Mockingbird. In summary, the narrator of and the one telling the story is the first-person narrator Holling Hoodhood who is telling the story from the near future (instead of distant future) while he is still a boy.