In 1969, Rick Dalton is an actor, and Cliff Booth is his stuntman. Dalton is relatively famous, especially for his leading role in Bounty Law, a western TV show on NBC, and for other starring film roles, mostly westerns.
In February, Dalton begins to realize that his career is changing, and he'll have to go from starring in American westerns to Italian westerns, something he despises.
One day, Dalton and Booth drive to the set of a Hollywood western. Booth, Dalton's driver, discovers he isn't needed for the day and drops him off. Driving away from the set, Booth sees a brown-haired young woman standing alone on the sidewalk, sticking her thumb out for a ride. Before today, Booth had seen this girl before, along with a few other girls her age. They made funny faces at him when he gestured no to them for a ride. However, today, Booth agrees to drive her. The brown-haired girl asks for a ride to her residence, an abandoned film ranch where she lives with other 20-ish boys and girls, all hippies.
Back on set, Dalton shoots the western, but forgets some of his lines. On break, he angrily yells to himself in his trailer, telling himself to stop drinking so he won't forget more lines. Later, when he's not needed for shooting, Dalton meets a little girl and talks with her about a book he's reading: a western where a man realizes something in his life is up.
Once Upon a Time… in Hollywood is one of Dalton and Booth's regular days, set during a time when they are both about to experience career and life changes. For Dalton, his career change means moving away from shooting American westerns and other American movies. Dalton doesn't take this change lightly, and he has moments when he starts crying as he thinks about it. For Booth, his career change comes from Dalton's.
Dalton and Booth are happy friends. Booth enjoys driving Dalton around, and the two happily drink and smoke together. Booth is generally happy; he smiles in a relaxed way a lot and is conversational with others, always there to talk.