Stacy Friedman is an exuberant young girl eagerly anticipating her bat mitzvah, dreaming of sharing the moment with her best friend, Lydia Rodriguez Katz, and securing a dance with her crush, Andy Goldfarb. However, her excitement leads to tension with her parents, Bree Friedman and Danny Friedman, who have their own ideas for a "perfect" celebration that Stacy believes is crucial for her future. With the help of her supportive older sister, Ronnie Friedman, Stacy navigates the ups and downs of teenage life.
Things take a turn when Lydia is invited to the house of popular girl [Kym Chang Cohen], with Stacy tagging along. The group ventures to a high ledge, where they meet up with Andy and his friends. In a moment to impress him, Stacy nervously takes on a dare to leap into the water below. While the exhilaration of fitting in brings her joy, it quickly turns into embarrassment when a bloody maxi-pad floats up beside her. Hurt and humiliated by Andy's laughter and the sight of Lydia joining in, Stacy decides to declare that her crush on Andy is officially over, with Lydia making the announcement.
Once the school year resumes, Stacy is devastated to discover that Lydia and Andy are now an item. Feeling betrayed, she stops communicating with Lydia, even spreading a rumor through an anonymous text about Lydia's personal grooming. In a misguided attempt at revenge, Stacy sabotages an "entrance video" for Lydia's bat mitzvah, filled with unflattering clips, but ultimately chooses not to send it.
Desperate to catch Andy's eye, Stacy attempts to present herself as older and more popular, leading to numerous arguments with her parents over her bat mitzvah's attractions and her wardrobe choices. Eventually, Andy invites Stacy to share her first kiss with him, but their moment is interrupted by Rabbi Rebecca, escalating the conflict between Stacy and Danny.
Compounding her troubles, Lydia's mother, Gabi Rodriguez Katz, unaware of the rift between the girls, requests the entrance video for Lydia’s bat mitzvah. Bree, not knowing what the video contains, unwittingly sends it. On the big day, the video is played at the festivities by DJ Schmuley, and despite Stacy’s frantic attempts to stop it, the damage is done. Lydia storms off, fuming at Stacy.
When the day of her bat mitzvah arrives, Stacy stands up to read from the Torah, only to find Lydia and her family absent. Driven by her emotions, she publicly confesses her feelings to the gathered crowd, criticizing Andy for his role in the fallout between her and Lydia. Encouraged by Danny, she completes her Torah reading, despite the turmoil.
Afterwards, Stacy rushes to make amends with Lydia, inviting her to the party later that evening. When Lydia and her family arrive, they are pleasantly surprised to discover the celebration has transformed into a joint party for both girls. The friendship is restored as they enjoy the festivities together, and Stacy starts dancing with Mateo, another boy who has often shown interest in her.
In a heartwarming conclusion, sometime later, Stacy, Lydia, and their friends host a bake sale to support the retirement home, showcasing the strength of their friendship and community bond.
