I don't think you necessarily need it when applying to a college. However, it is good to have when you are planning to apply for a job. We will be having a career fair this Fall so if you have it before then, you'll be set!
Malyka, it's great that you have developed a cover letter and resume! I would love to see it. You are already doing a self inventory of the skills and abilities you have. It's an excellent way for you to monitor your growth and take charge of your professional and personal development.
You're ahead of the game, Malyka! One of the nice things about MSOE is you will be taking classes in your major during the first year. Sometimes that can lead to summer internship opportunities, and your resume and cover letter will be important marketing tools. Bring them by the Career Services Office when you get to campus in the fall.