Another work of literature with which you might be more familiar is Harper Lee's To Kill a Mockingbird. Near the end of the novel, when Scout stands on Boo Radley's front porch and looks out over the town of Maycomb she sees herself, her town, and the world as a whole from a completely new perspective. This is her epiphany.
As Scout narrates:
I turned to go home. Street lights winked down the street all the way to town. I had never seen our neighborhood from this angle. There were Miss Maudie's, Miss Stephanie's--there was our house, I could see the porch swing--Miss Rachel's house was beyond us, plainly visible. I could even see Mrs. Dubose's. [...]
Atticus was right. One time he said you never really know a man until you stand in his shoes and walk around in them. Just standing on the Radley proch was enough.
We see in this short scene the full weight of the entire plot of To Kill a Mockingbird come crashing into Scout's consciousness. She is a changed young woman because of her experience; she has grown up, lost her innocence, and gained her epiphany.
I agree that given the grade where you are, the classical examples of epiphanies in literature might not have been introduced to you. Don't worry, they will be. I will try to take this in terms of Young Adult Literature that could be relevant to you and then go classical with it. I think that Melinda's series of epiphanies in Anderson's "Speak" that help to define who she is and her eventual confrontation with "it" are powerful moments of self awareness and change. At the same time, Brian Robeson's epiphany into "tough hope" in Paulsen's "Hatchet" is compelling in the formation of his identity. In terms of classical literature, Hektor's speech to the Gods, right before he dies and holding his child in his hands, is a moment of epiphany in Homer's "Iliad." At the same time, Stephen Daedalus goes through epiphany after epiphany in "A Portrait of the Artist as a Young Man." When Sethe responds to Paul D with her query of "I am," at the end of Morrison's "Beloved," we, as the reader, want to read an epiphany in play, a moment of stunning change and realization. Finally, Tony Kushner's play, "Angels in America," defines epiphany as "the threshold of realization." This is something that every character endures to a certain extent, and something that Kushner thinks America experienced with its own coming of age about issues of identity and sexuality.
There is a very short story called "The Flowers" by Alice Walker. In the story a young African-American girl is walking around her home and playing childish little games. She wanders a little farther from her normal area and starts to collect pretty wild flowers for an impromptu bouquet. All of a sudden she sees some wild pick roses, but as she steps forward to pick them she steps in the skull of human skeleton. She is shocked, but not disgusted and she lays down her bouquet in a kind of reference to him. The epiphany of her story comes when she looks up from the body and sees the frayed remains of a rope. It is left implied, but if she realizes that this is the location of a lynching she certainly has an epiphany in regards to the cruelty of life in this place.
One of my favorite examples of epiphany is that of the narrator in Alice Walker's "Everyday Use." This is a very brief short story in which the narrator realizes which of her daughters is more deserving of the heirloom quilts she owns. While one fashionably coifed daughter wants the quilts to hang on walls; the other plainer daughter wants them because her grandmother made them. It's the way that Walker describes the mother's (the narrator) realization that makes it such a perfect example of an epiphany:
When I looked at her like that something hit me in the top of my head ran down to the soles of my feet. Just like when I'm in church and the spirit of God touches me and I get happy and shout. I did something I never had done before: hugged Maggie to me . . .
The ending is quite satisfying because through the mother's epiphany, the daughter who truly deserves the quilts is the one to receive them. Up until then, the mother had favored the other daughter, had never said no to Dee. But at the story's end, it is Maggie, the underdog, who wins.
A collection of narratives in which characters experience epiphanies is in James Joyce's The Dubliners, a compliation of stories about the tragic Irish, whom Joyce characterizes with their brown lives as possessing a kind of paralysis. One story, entitled "Eveline" for instance, presents a nineteen-year-old girl who dreams of escaping an abusive father by traveling to America with her boyfriend, a sailor. However, at the moment that they are to board the ship, Eveline becomes paralyzed as she fears leaving her brother and breaking a promise to her dead mother. Eveline's epiphany, or moment of truth, is the realization that she is not going to run off. Instead, she will return to her dismal and desperate life.
Another author who has characters who experience epiphanies of salvation, are in Flannery O'Connor's Southern Gothic short stories. In one story, "A Good Man is Hard to Find," a self-absorbed grandmother encounters the "Southern grotesque": the Misfit, who claims that Jesus "throwed everything off. Oddly enough, it is by looking at and listening to the Misfit that the grandmother achieves grace, telling him, "Why you're one of my children!" and she is saved as she abandons her hypocrisy.
This is a great question, though I see you're in 9th grade and some of my best examples may be from things you haven't yet read. An epiphany, of course, is a moment of awakening, of realization, which generally changes a person's motives, outlook, actions, and/or thinking. It may be triggered by something big or small, and it often happens in private rather than in public.
In Romeo and Juliet, the feuding families have a sort of epiphany when they realize their children have died for their foolish enmity. The Capulets and the Montagues are sworn enemies until they step into the tomb and see what their hate has caused. At that moment, they each vow to honor the other's fallen child in some public way.
In Oedipus, King Oediupus has an epiphany when he suddenly realizes he is the one who has brought a curse upon his town by inadvertently killing his father and marrying his mother. When he realizes it is he who is the curse, he immediately blinds himself because he can no longer bear to see his own face after the horrors he has committed.
In The Crucible, John Proctor has an epiphany when he has to either sign his name to a lie or die. He believes he is already a sinner of the worst sort, so he signs his name to the false confession. Almost as soon as he does, he has an epiphany in which he understands that God will forgive his sins and he will die as a forgiven man. He then tears up his false confession, thus sealing his own fate--death on this earth but eternity in Heaven.
In Animal Farm, Benjamin the donkey is a rather quiet animal, totally dedicated to his friend Boxer the horse. Boxer is symbolic of the working man in this allegory, and Benjamin represents the academic or scholarly people in the country. When Boxer has literally been worked to death, the animals are told he is being taken away to the hospital. Instead, though, the dying horse is being taken to the knacker's to be butchered for his parts. Benjamin can read, and when he sees the name on the side of the cart, he has his epiphany. He understands they have all been lied to, and that if Boxer leaves the farm he will never return. Benjamin raises the alarm and rallies the animals, but his moment of understanding comes too late.
There are lots and lots of similar examples throughout literature, but I'm hesitant to give you too many from things I'm guessing you haven't read yet. Hope this was helpful to get you started thinking about epiphanies. I'm confident that, looking back at other things you've read, you'll find even more examples.
An example of an epiphany in literature would be from the book The Lord of the Flies. A couple of the character's par take in a revelation of their own. Ralph, usually seen as the leader, has one where he is staring at the ocean and realizes that even though they constantly hope to be rescued there is a huge possibility that they may never leave the island. There is also Simon who is constantly worrying about how the boys are turning more towards their evil nature but then has an epiphany realizing that the boys are the beast and the beast are the boys.
Oedipus is one of the most important epiphanies. The entire time Oedipus does his best to leave the fate he is cursed with and moves to another town. In the process he completes some parts of his fate and destiny, which is his ultimate downfall. When he believes that there is no way he could have killed the King, because this would have meant that he was his mother's son husband. When the truth is unveiled and he realizes what he has done as well as all of the pieces fitting together, he is in shock and appalled. To make sure he would look upon no one else and see them looking at him with disgust/pity, he ends up blinding himself.