I can definitely help you get started on your essay, but the writing needs to be yours. Plagiarism would be an issue, if I wrote something for you, and you took it as your own. Additionally, teachers are smart people. Your teacher likely has a good sense of what your writing "voice" sounds like, so it's important that your piece is written by you.
I can't begin to guess which character you admire the most in the story. I know that I admire Mr. Robinson the most. He has all kinds of wonderful character traits. He's patient, intelligent, good with science, and a kind father. The last part is probably why I admire him the most. I'm a dad too, so it makes sense that I relate best with another father character.
For your essay, choose which character that you either like the most, or the character that you think is most similar to you. Then your job as a writer is to explain to your reader why you chose that character as the most admirable character in the story. Picking the character is the short part. Explaining why is what your essay is going to be about.
Write the introductory paragraph that tells your reader which character you are going to analyse. Finish that paragraph with a statement that tells your reader the three main reasons why you admire that character the most. "Mrs. Robinson is a very admirable character because she is something, something, and something." The next three paragraphs will discuss each of those reasons. Use quotes from the story to help support your argument.