Twain's Humor

What is the essential idea of the "prefatory"?

This is simply a book about personal narrative and also a record of several years of variegated vagabondizing. and it also says that there is information in everything 

Find one example of humorous word choice and explain what makes it humorous in Chapter 42?

One humorous example was when the character tells that  I must presently become dependent upon somebody for my bread, a thing necessarily distasteful to a man who had never experienced such a humiliation since he was thirteen 

years old. Not much to be proud of, since it is so common 
—but then it was all I had to be proud of.

Explain how the sentence structure of the two readings contributes to a humorous tone?

The structure of two readings contributes to a humorous tone because the author keeps joking about all the work failures he has gone through and also about his childhood.

Explain how Twain's use of figurative language/literary devices creates humor in Chapter 42?

Use of figurative language creates humor because he is making fun of himself and also about his life