At the party.
at first she doesn't, but he tells her he is there eventually
Juliet's Nurse tells Romeo that Juliet is a Capulet, while Romeo's friend Benvolio reveals to Juliet that Romeo is a Montague.
Juliet's Nurse tells both Romeo and Juliet who the other's identity was.
They both learn their respective identities from the nurse: Romeo first, then Juliet.
Romeo's servant Balthazar tells him the news from Verona.
Benvolio tells Romeo that Juliet is a Capulet at the party.
The first thing that happens in Act V is that Romeo tells us about a dream he had.
Her first assumption is that Romeo has been killed.
Balthasar
The Nurse
Romeo's friend Balthasar tells him
Benvolio(Romeo's Cousin), tells Romeo to forget Rosaline (Romeo's love before he met Juliet) and to go to the Capulet's party to meet other girls