When writing an essay about two novels that seem to have very little in common, the first step must be to find out how they are, in fact, similar. For The Catcher in the Rye and Fahrenheit 451, the best way to determine similarity is to look at the novels' protagonists, Holden Caulfield and Guy Montag. While the easiest way to answer this question is to look at thematic similarities—both characters face serious alienation from society—I would want to look at something in the plot that happens to both Holden and Montag: the fact that they can not go back home. Now, even though it seems like I'm writing about plot, which is a big no-no when in literary analyses, I will be focusing on symbols and themes throughout.
Note about comparison-contrast essays: since your teacher wants five paragraphs, you should follow the topic-by-topic method. Here's an example:
- Paragraph 1 - Intro with arguable thesis statement.
- Body Paragraph 1 - Topic 1 (characters' views of "home")
-- Holden's view of "home"
-- Montag's view of "home"
- Body Paragraph 2 - Topic 2
- Body Paragraph 3 - Topic 3
- Conclusion (Restate argument and tell your audience why they should care)
To start this five paragraph essay, I'd write an introduction that with a three or four sentences summary of how Holden and Montag, because of choices they make, cannot go home.
In my first body paragraph I would start with how Holden and Montag are both concerned about the idea of "home." For example, one of the most well-known symbols in Catcher is the idea of the ducks in the pond. Holden asks several characters a variation of "what happens to the ducks in the pond when it freezes over?" In Fahrenheit, Montag walks into his home and realizes how cold it feels. After his conversation with Clarisse, the narrator describes Montag's home as in "complete darkness" and "the chamber of a tomb-world where no sound from the great city could penetrate." Of course I'd have to make greater connections and tie the seemingly separate ideas together.
After this, I would probably move on to talk about how both of the characters are not welcome at their homes. Then my final body paragraph would focus on, maybe, on how at the end of both novels, both Montag and Holden finish homeless—Holden in a mental hospital and Montag in the wilderness.
There are many other ways you can approach this topic, but you will probably have to focus on character.