“But all so soon as the all-cheering sun should in the farthest East begin to draw the shady curtains from Aurora’s bed.” This line refers to Aurora the Roman goddess of dawn.
In the line,” She’ll not be hit/with Cupid’s arrow.” Romeo refers to Cupid a Roman god of love and passion. Rosaline once again rejecting Romeos sexual advances. “I have night’s cloak to hide me from their eyes.” The night is dark and will keep him hidden from Juliet’s family.
“Two of the fairest stars in all the heaven, /having some business, do entreat her eyes/to twinkle in their spheres till they return.” Juliet has eyes that sparkle like stars and Romeo is dazzled by them.
“Her vestal livery is but sick and green and none but fouls do wear