Jane Austen uses comedy in Pride and Prejudice to illustrate the folly of British society of her time. It is quite humorous to observe the courting ritual of Mr. Collins when he circles Elizabeth Bennett. Jane Austen, observed society, she studied people and had a unique perspective from which to report. As an unmarried woman, who was courted, she illustrates how many women of her society accepted the clumsy courtship of men like Mr. Collins so that they would not end up as spinsters. Mrs. Bennett is also a comical character, forcing the reader to understand the intense pressure from British society for a girl to marry. Mrs. Bennett is consumed with nerves at the thought of having to marry off her daughters. It is further compounded by her husband's lack of interest in the subject. Therefore, comedy or satire is employed as a literary tool to draw the reader's attention to the image of a society that placed more importance on marrying well, rather than on the concept of love being the driving force for marriage. Love, is important to Lizzie, so when Mr. Collins tries to corner her into a marriage of convenience, the reader knows that it is only to make us laugh at his folly, and that of the society in which he lives.
One character who is humorous at times is Lydia, Lizzy's youngest sister. She is portrayed as a what we used to call an "airhead"; all she thinks about is clothes and parties and flirting with boys, preferably soldiers. Her nonsense leads her to fall for Wickham and his stories, so much so that she runs away with him. She is a younger version of her mother, who overreacts and is given to histrionics.
Mr. Collins is a comical character as well. He is so prim and proper and always chooses his words carefully. For a minister, who should not care for worldly things, he is overly concerned with status and appearing more important than he is. He constantly quotes Lady Catherine de Burgh to impress people and make them feel as if he is on her level.
I think Austen very definitely meant to make her characters "funny." She uses Lydia and Mr. Collins to satirize marriage. It was so important for a woman to marry in Austen's time, but Austen wanted us to see how that was not necessarily a good thing for everyone.