In this scene, we learn that Antonio is in love with the beautiful Portia, but in order to win her love, he thinks he needs to become wealtheir so that he can compete with her other suitors. He is already in debt. He is with his friend Salarino and they are talking about his business endeavors when they run into Antonio's relative, Bassanio, who tells Antonio he cannot give him another loan. The mood set in this scene is one of desperation.
I'll get you started on some of the language that Shakespeare uses in the scene, and you can take it from there.
In sooth, I know not why I am so sad;
It wearies me; you say it wearies you;
But how I caught it, found it, or came by it,
What stuff 'tis made of, whereof it is born,
I am to learn;
Here, the emotion of "sadness" is given life (personified). Where does the sadness come from? How was it "born" is making it seem as if it is human.
Your mind is tossing on the ocean;
There, where your argosies, with portly sail,—
There is a metaphor in these lines. The picture is of confusion, but the mind is compared to a ship tossing on the ocean.
Believe me, sir, had I such venture forth,(15)
The better part of my affections would
Be with my hopes abroad. I should be still
Plucking the grass, to know where sits the wind;
In the above lines, Salario tells Antonio that if he were involved in merchant ships, it would make him sad. Notice the imagery - he says that he would be so worried that it would cause him to "pluck grass to know where sits the wind" - this means that he would be checking to see how the wind is blowing the grass and in what direction, to check on how his ships would be doing at sea. It's a cool image, don't you think?
Try to go through the scene yourself to find other figurative language. Look for the words "like" and "as" to pick out similes. These are easier, so I left them for you!
You can read the enhanced text of the play here on enotes. See the link below.