WHAT HAPPENS AT THE START OF A FILM?

Here are a list of common things that happen at the start of a film:

• The setting and location is shown, so the audience know where the storyline is taking place.
• Plot/storyline
•  Establishing shot
• Title
• Music (especially in teen movies)
• The main characters are introduced at the start of the film and also the role they play is also established at the start of the film
• Film identity
• Narrator (Yes in some teen films)

Some examples (All examples are used from teen films):

Main characters are used in all teen films and the role each character plays is usually established at the beginning of the film (example, ) . 'Main character' introduction and 'setting and location' can be seen in 21 JUMP STREET and JUNO.
Here is the clip from Juno

Juno (2007) — Art of the Title

Another example i found was music, titles and also introduction a main characters in THE PERKS OF BEING A WALLFLOWER AND NAPOLEON DYNAMITE

Music: 


Music and character : Napoleon Dynamite (2004) — Art of the Title

'Narrator' can is used in some teen films but it is not very commonly used..A good example of when 'narrator' is used at the start of a film is in the film WARM BODIES