General codes and conventions of film openings

SelfContained narrative sections are used commonly in film openings.
The Main character/Central Potagonist is introduced to be the first character on screen, showing their importance and reasoning in the film you are about to watch. This occurs in many films and is a very common factor e.g Anchorman and Hotfuzz.

Voice overs often come on over blank screens to give us a sense of exposition ( Divorcing Jack), they also use titles to give us a sense of expostion e.g what year, location or what time (Halloween, Clerks and Club Dread)
Creative ways to give exposition is used such as putting  location on signs/posts and walls or a famous example would be napolen dynamite using food.

Many films do not follow a chronological order, e.g starting with end first then beginning then middle (Severance)

Most films follow todorovs theory of three stages, Equilibrium, Disequilibrium, and new equilibrium.