What does the following quote say about the narrator’s self-image? “I have entered high school with the wrong hair, the wrong clothes, the wrong attitude.” (p. 4)

This quotation comes in the opening chapter of Speak by Laurie Halse Anderson. The words are spoken by Melinda, the story's deeply troubled protagonist. It's her first day at Merryweather High, and she's understandably nervous. Traumatized by her recent sexual assault, she feels completely alone and friendless in the world. As she sits by herself on the school bus, it's painfully clear that she's been ostracized by the kids she once knew in middle school; they just don't want to know her anymore.
Right from the start, then, it's obvious to Melinda that she doesn't belong in her new environment, and that's a pretty serious matter, as belonging is everything in high school. This initial impression is confirmed when Melinda, with all the other ninth-graders, gathers in the auditorium for an assembly. Straight away, she notices that everyone is huddled together in their own little social group—all except Melinda, that is. She sits all alone, isolated from the other students by her hair, her clothes, and her attitude, all of which are completely wrong for Merryweather High.
It's clear from what Melinda says that she has a very poor self-image and a dangerously low level of self-esteem. This isn't at all surprising given the appalling ordeal she suffered and with which she's still struggling to come to terms, not to mention her sudden abandonment by the people she thought were her friends.