Whether you choose correspondence teaching or amateur teaching, you need to go to school.
Each semester is about three or four days, six or seven days, one to two months. It depends on colleges and majors.
However, the policy is currently in the reform stage. Some colleges and universities do not need students to attend classes at school, but implement online video teaching on the Internet all the time. In the form of recorded courseware, they can log on to the designated learning website for learning and watching.