Hi! We can't help you on which stories to write about because we don't know what you discussed in class or which stories you've read in the semester, but the assignment here tells you to pick from the stories you've read and relate it to those quotations you were given.
Pick the story you liked the most, analyze the main characters and see how in that story they are created and developed in context. What the quotations say is that you can't draw a character without any context, the characters live in a certain place, with certain people (or alone, that would also tell the reader something about him or her), has some favourite activities, etc. From all those characteristics you give to the personality and the context you create for it, the reader can form a vivid image of how he or she is.
As you know, people, in the real life, are social animals. All of us live in society, and how we act and interact with others says a lot about our personalities. The same has to happen when you develop a character in a story. You have to create a context and show how this character interacts with the outside. This will help readers to build a vivid image of each one and the story will be more consistent.
