I require 2 examples of how Romeo, Juliet, Tybalt, and Friar Lawrence show impulsive behavior that results in personal struggle. I require this information to be able to write a literary essay.

Romeo shows impulsive behavior when he decides, after laying eyes on Juliet a single time, to go to her window. As Juliet points out, it would mean death if he is caught.
Another example of his impulsiveness is his decision to immediately buy poison and return to Verona to kill himself when he hears that Juliet is dead. He makes no attempt to verify this news but rushes back to end his life.
Juliet is somewhat more mature and measured than Romeo, but her decision to marry him is fairly impulsive. After all, she has only met Romeo once, and she knows that he is from the rival Montagues.
One might also argue that her decision to accept the Friar's plot is impulsive, though events had very much conspired against her at that point: Romeo had been banished and her father had promised her hand to Paris.
Tybalt is one of the play's most impulsive and hotheaded characters. He demonstrates this at the Capulet family masque, where he recognizes Romeo. He wants to kill him and chafes at Lord Capulet's instructions to leave Romeo alone.
He later takes to the streets to find Romeo despite the order of the Prince that anyone fighting in the streets faced a potential death sentence.
Finally, Friar Laurence is impulsive in his decision to marry Romeo and Juliet, though his heart is in the right place. He hopes their marriage will reconcile their two feuding families.
He is also impulsive in his planning once Romeo is banished. A more sober assessment of the situation might have suggested that the plan was very far-fetched and unlikely to work. Each of these impulsive acts helps to drive the plot toward its tragic conclusion: the deaths of Romeo and Juliet.