Nancy chases after Will as he bike off with the change he stole from her piggy bank in episode 2x01 “Chapter One: Madmax”. Eleven shows up at Mike's house after defeating the demogorgon and finds the feds telling the family a story about her in episode 2x02 “Chapter Two: Trick or Treat, Freak”. Nancy heads out with Jonathan on their way to the park in episode 2x04 “Chapter Four: Will the Wise”.
Appears in 15 additional episodes.
Dustin rides to Mike's house looking for him for help with Dart and ends up recruiting Steve.
Billy talks to Karen Wheeler and gets the address of the Byers house.
Mike follows Will outside to apologize for ignoring his D&D game
Max and Eleven ride to meet the boys after they call the Code Red.
All the kids pile into Nancy's car so she can drive them out to the Holloway house.
Also appears in “Chapter One: The Vanishing of Will Beyers”, “Chapter Two: The Weirdo on Maple Street”, “Chapter Three: Holly, Jolly”, “Chapter Five: The Flea and the Acrobat”, “Chapter Six: The Monster”, “Chapter Seven: The Bathtub”, “Chapter Eight: The Upside Down”, “Chapter Four: Dear Billy”, “Chapter Six: The Dive”, & “Chapter Seven: The Massacre at Hawkins Lab”.
Source: Stranger Things — Wikia