thank you for picking a play I've actually read for this
Now, consider Juliet's position: she has met whom she believes - no, knows - to be the love of her life, and the one thing to stand in the way between her and him is the petty, nonsensical feud between their families. Neither Juliet nor Romeo wish to partake in it, yet by virtue of their birth, by pure chance alone, their reunion cannot be.
"Wherefore art thou Romeo" - why art thou Romeo? Consider her mention of his father: she protests the fate that binds Romeo to his family name and, consequently, to their feud. Such a cruel trick of fate, to have born them on opposing sides, when nothing would stand in the way of their love had but one of them been of a different family.
Consider the strength and desperation of her wish to be with him: for the sake of his love, she, a mere child, is prepared to reject her family, her entire world - "and I'll no longer be a Capulet".
[Adjusting his glasses before continuing:] You see why it is necessary to pour all of one's heart into this scene. If you must, draw inspiration from your own life experiences. Now, again, please.