In order to complete a summary about your favorite character, you will first have to select one. Do you identify with one of the characters? Is there a character that you admire? For example, you might say that you identify with Nick because he is creative and does not give up his idea to call pens "frindles" even when he faces getting into trouble. You might say that you admire Mrs. Granger because in the end, she tells Nick how she believed in him, even though she had him tricked to think otherwise for years. She explains that she supported him almost all along, even though she did it in secret.
Once you select your character, you will have to provide several details and examples to explain why they are your favorite. Look for both specific details and overall ideas to use for examples from the book.