I don't understand your question. I don't know any term "commentary essay." Do you mean an essay that presents your personal opinion, as opposed to a news story that presents facts? Often, a teacher wants to see you justify your opinions by providing supporting facts. Don't just state your opinions. Give the reader reasons for agreeing with you. With regard to structure, we are often told: "Tell your audience what you are going to say. Say it. Then tell them what you said." Begin each paragraph with a "topic sentence." Begin the whole essay with an introductory paragraph that "tells what you are going to say." End with a summary paragraph that "tells them what you said." If possible, and if it is not against the rules, have a friend read your essay and see if they understand what you are saying.