FIRST: Mercutio delivers a monologue about Queen Mab.
SECOND: Romeo and Juliet meet.
THIRD: Tybalt argues with Capulet about Romeo.
FOURTH: Lady Capulet discusses Paris with Juliet and the Nurse.
The chronological order of events in the story would be:
Mercutio delivers a monologue about Queen Mab.
Romeo and Juliet meet.
Tybalt argues with Capulet about Romeo.
Lady Capulet discusses Paris with Juliet and the Nurse.