I agree with the previous post: Most of these are major characters in the novel and should be familiar if you have read these chapters. However, here are a few helpful facts about some of the characters:
MISS CAROLINE. Scout's first grade teacher. She is a new teacher and a newcomer to Maycomb, so her first day is a true learning experience for her.
BURRIS EWELL. The son of Bob Ewell, Burris comes to school filthy and with his head full of lice. He threatens and curses Miss Caroline before leaving early on the first day.
WALTER CUNNINGHAM. Walter Sr. is a hard-working farmer who will reappear in the later chapters. Atticus has represented him legally in the past.
WALTER CUNNINGHAM JR. Don't confuse Jr. with his father. Walter Jr. is a classmate of Scout's who she defends on the first day of school. When she gets in trouble with Miss Caroline for this, she beats Walter up and then invites him to lunch.
I think the idea here is for you to actually read these chapters and distinguish who is who and what is what. All of these are pretty major details and major characters. In fact, with the exception of Miss Caroline and Burris (Ewell), all are mentioned throughout the rest of the novel.
It would be helpful for you to jot a few notes down about each one as you read to keep track of everyone, especially at the very beginning. By the end of the story though, you won't need to consult these notes anymore. I assume these are all details you will be quizzed and tested on, however, as they are key details.