The play Romeo and Juliet opens with a fight scene between the servants of the Montagues and Capulets. The purpose of this scene is to demonstrate how deep the hatred goes between the families. It's not just blood relatives fighting but any member of the household and its staff. Even the governing body of Verona, Prince Escalus, has trouble controlling the feud. By starting with their "new mutiny" that fuels the "ancient grudge", it develops the obstacle that Romeo and Juliet must overcome if they want to be together.
In the begin of Act 1 Romeo is lovesick. He thinks that nothing will replace his love. Juliet is a girl of her dreams. She doesn't want to marry anyone but when the two met each other at the masquerade ball, it was love at first sight