Bradbury uses a lot of poetic and figurative language in his writing, so the book has many, many different similes in it. I'll jot down several, just in the opening sections, to get you started. In describing Clarrisse's face after Montag gets home after meeting her for the first time, Bradbury writes,
"She had a very thin face like the dial of a small clock seen faintly in a dark room in the middle of the night...with a white silence and a glowing, all certainty and knowing."
This simile (comparing two things using like or as) relays the fact that Montag feels assured and comforted by Clarisse; she is knowing, and a beacon of assurance in a dark world. Bradbury goes on with another simile for Clarisse's face: "how like a mirror, too, her face," meaning that she had the ability to help people see themselves for who they really are. Again, on Clarisse:
"she was like the eager watcher of a marionatte show, anticipating...before it began,"
meaning that she is an observer of their world, curiously watching what is going on, and able to understand everyone's movements. Later, as he comes steps into his bedroom,
"he felt his smile slide away, melt, fold over and down on itself like a tallow skin, like the stuff of a fantastic candle burning too long and now collapsing and now blown out."
This symbolizes his unhappiness in his own home, after the soft, burning happiness of talking to Clarisse.
Bradbury uses similes all throughout his novel, and if you keep your eyes open for them, they almost always convey a deeper symbolism for the characters and the moments they experiences. I hope that helps a bit!