Sorry in advance. I remember only a part of the plot and some scenes, further, not sure about it is film for TV or theaters, and further, it doesn’t seem to be very acclaimed.
1.- The main character, a female teenager, too relates voice-over parts of the story, completing it.
2.- Maybe the plot runs in a small american village. She has a very close friend who starts to avoid her, clearly because she feels now great attraction to boys, in special to a common friend of them. The main character expresses frustration and lack of understanding about the new strong interest about boys.
3.- [Important parts of the plot missing]
4.- Somehow the main character ends in a boarding school where she knows, and gets, a new very best girlfriend.