Two quotes come to mind reflecting freedom of choice, but in reality, choice is limited.
Romeo bucks his friend Mercutio's advice on affairs of the heart in favor of his own choice. In 1.2,102-103, he defends himself, saying: "I'll go along, no such sight to be shown,/But to rejoice in spendour of mine own." Here, Romeo claims to have maturity to choose his love, but he is anything but mature. As recently as 1.1, he is mooning over his lost love, Rosalind. Only one who is versed in the art of love can claim to be able to make a clear choice. Romeo is more motivated by his romantic illusions than by thoughtful choice.
In 1.3.17-18, Juliet's father allegedly offers his daughter the freedom to choose a mate. He says: "My will to her consent is but a part, And she agreed, within the scope of her choice/Lies my consent and fair according voice." However, Lord Capulet has, in truth, already selected his daughter's future husband, Paris, and has no doubt that "(m)y will to her consent is but a part" and moreover, she is only free to select a mate "within her scope of choice," ie, one Capulet has sanctioned (clearly, this *won't* be his ancient enemy, Montague's son, Romeo.)