They both learn their respective identities from the nurse: Romeo first, then Juliet.
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.
Balthasar, Romeo's servant, brings the news of Juliet's death.
Friar Lawrence wants Romeo to do different things depending on what part of the play you are talking about. When they first meet, the friar tells Romeo to go slowly in his relationship with Juliet (as if!).
The Nurse.
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.
at first she doesn't, but he tells her he is there eventually
At the party.
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
Romeo's servant Balthazar tells him the news from Verona.
Benvolio tells Romeo that Juliet is a Capulet at the party.
He tells him to look for other girls
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