In The Terminator, Sarah Connor is working as a waitress at the start of the film.
Sarah is initially presented as an ordinary young woman in Los Angeles, unaware that she has become the target of a future assassination attempt. Her job helps establish the contrast between her everyday life and the time-travel conflict surrounding her.
The film later transforms Sarah from a frightened target into a determined survivor. Her experiences with Kyle Reese and the Terminator reveal that her future son, John Connor, will become the leader of the human resistance.
Sarah's occupation is sometimes confused with her later identity as a waitress who becomes a fighter. The answer refers specifically to her job before the main events change her life.