How can someone become a U.S citizen?

I am from Trinidad and I would like to become a U.S citizen. I am in college pursuing a bachelors degree in teaching and I would like to teach in New York but I don’t know how to go about getting citizenship. I have a sister that is a permanent resident up there, but I am not sure she can file for me. I wish to migrate when I have completed the course that I am taking which will be next year. Is there any possible way I can make this dream of mine come true? Can I achieve citizenship up there and work as a teacher? If so…what are the steps that I have to take?