First-year students follow two different processes for registration for the fall and spring semesters. For the fall semester, your First Year advisor will enter build your schedule for you. In the spring, you will use the online registration system yourself to select courses, but only after meeting with your advisor.
You must follow the registration process carefully to be sure that you are meeting your First Year requirements. In your Sophomore year, you will work with the advisor of your chosen undergraduate program. See list here.