You answer the question, "What is your impression of the narrator?" by thinking about your reaction to what you have just read. The question is asking for your opinion, which means there is not going to be one right answer to the question. You need to analyze your feelings and determine your impression, then identify and give supporting reasons to justify your response.
Ask yourself, based on the way the narrator talks and what s/he does during the story, do I like him/her? Why or why not? Do I trust him/her? Would I enjoy going on a trip with him/her? Why or why not? Would I want to work with him/her? Why or why not?
Based on your answers to those kinds of questions, you should be able to explain your impression and why you feel that way about the narrator of your story.