the beginning followed by the middle the the end
Holden is attending Pencey Prep at the beginning of the story.
Introduction Exposition (formal name)
Same story, new name.
Usually you call the name of a story the title - unless it's a nonfiction work, in which case it might also be a heading or sub-heading underneath the main title.
Starting in medias res
In the beginning of West Side story, the story begins. LOL.
Carlos and Anna are in the park at the beginning of the story.
The story transitions from the beginning to the middle when the occurs
His name is Officer Krupke and he has a song later in the show.
How has Bud changed since the beginning of the story
the narrator is in prison for the first time.
The full story is the entire story, from beginning to end.