This is what I have to do:
Discuss the characterization in the novel. Identify the protagonist and antagonist. Are the main characters round or flat? What are some of the main characteristics of the protagonist? Is he or she a sympathetic character? Organize your response so that you have a clear introduction with thesis statement, supporting paragraphs, and conclusion. Use quotes and examples from the text to explain and illustrate your point of view.
I can't seem to put it into words. Please help me.

Help you with what? You are the one writing the thesis, not me so I haven't the faintest clue what your topic is.

Just carefully re-read each of the statements you made above and think them out in a rational way. There is always a beginning, a middle, an end, and a conclusion to everything. One word at a time will build up whatever picture you want to project. You can always start with a draft of this and keep re-working the draft and fleshing it out until you are happy with it. Some people like to put their ideas down on a paper like it's a picture having different pictures all over the paper representing each new idea or topic that needs to be covered.

Try making up an outline of the points you want to make. When you know all the points you want to make, then try to write your thesis so that it sums it all up. There is a really good book that helped me with writing essays. It is called 'Writers Inc.' They gave it to us back in high school and I always kept it because it helped so much.