Your teacher is asking you to look at the similarities between real fireman and the fireman in Faranheit 451. Sometimes, however, teachers are also looking for some differences. Look at the question carefully.
The length of your paper isn't mentioned but can be determined by how many traits you want to discuss.
Start with tasks (what are the daily tasks of real fireman and what are the daily tasks of fireman in the text). Make a list, when you find tasks on both lists, discuss these. You can then move onto emotional aspects of firemen, etc.
There are striking differences between firemen in our world and the main character, Montag. "An atmosphere of alienation is established by Bradbury in the opening scenes of Fahrenheit 451, which details a "fireman's" growing dissatisfaction with his conformist society. Montag's pleasure in his work of burning books is quickly challenged in his conversation with his neighbor, Clarisse McClellan" (e-notes).
Quotes from the text are helpful in proving your ideas and major themes. Check out the following reference links for additional help with themes.