Three types of figures of speech found in Don't Look Behind You are imagery, similes, and hyperbole.
Imagery is the author's use of vivid description to create a striking mental representation for readers. One example occurs when Steve asks April to dance in the first chapter:
His cheek was smooth against mine, and his breath smelled faintly of chocolate, and a piece of tinsel from the Christmas tree was caught in his thick, dark hair. Over his shoulder the tree lights twinkled like red and green fireflies, and beyond that the fire filled the room with a golden glow.
In this passage, there is tactile imagery as April describes Steve's cheek. There is olfactory imagery in the description of his breath. Visual imagery is used to describe the lights, the glow of the fire, and the tinsel in his hair. This combination of various forms of imagery creates a vivid mental picture for readers, which is important in establishing the tenderness of this moment.
This passage also employs a simile, which is a comparison of two unlike objects using the words like or as:
the tree lights twinkled like red and green fireflies ...
By comparing the twinkling trees to fireflies, the scene seems more natural and even innocent.
Another passage that contains both great imagery and a simile is found in chapter 2 as April glances back at her house while she is driving away:
Our house was positioned in the center of the glass like a painting in a frame, and the whole front yard was ablaze with the brilliance of springtime. The last of the red and yellow tulips, the first of the bearded iris, pansies, azaleas, and crocuses overflowed the flower beds. The purple leaf plum and the tulip poplar were at the peak of their bloom, and the whole side yard was one solid mass of pink dogwood.
The simile comparing the view through the back window to a "painting in a frame" captures the inherent beauty and importance of her home. The imagery describing the various flowers and trees that color the landscape of her yard creates a mood of warmth and joy associated with the family home.
Another simile is found at the end of chapter 1 as April surveys the scene inside the counselor's office:
On a bench opposite the doorway two boys with bloody noses sat glaring at each other, obviously longing for a chance to continue their fistfight. Farther down on the bench sat a sullen red-haired girl, chomping gum like a riveting machine.
This comparison illustrates the mechanical, mindless rhythm of the girl's gum chewing.
The novel also employs hyperbole, which is a great exaggeration that is not meant to be taken literally. April recalls the smile of her uncle, Max:
In every memory I had of him, Max had a smile on his face, wide and white, almost blinding in its intensity.
Of course, her uncle's smile doesn't literally blind her, but this exaggeration helps to characterize Max as friendly and fun-loving.
I hope this helps as you look for other examples of figures of speech in this novel. Good luck!