@cutie-cat leaving secondary school and entering postsecondary study is a big adjustment for many students. If your student is aware of some of these differences, they will be better prepared for the changes 
in attitudes and behaviours necessary for success. Some of the differences between high school and university are as follows:

Classes are usually larger than those in secondary school and there are many more students on the university campus.
Students are responsible for making their own class schedules and following them conscientiously.
Instruction is primarily through lecture format with students taking notes independently.
Familiarity with library resources and effective use of libraries is essential.
Student progress and attendance is not generally closely monitored by instructors.
Students need to be self-directed and are expected to be independent.
There is, generally, less ongoing contact with instructors and less individual attention unless initiated by students.
There are fewer hours of in-class time and many more hours of homework and independent study per course.
Classes may have a lab or tutorial session located in a different room or building, and may be facilitated by a teaching assistant.
Professors and teaching assistants often hold office hours each week for students to drop in to chat or ask questions about assignments and class topics.
Course textbooks or required readings are not provided by the University; they must be purchased from a bookstore or borrowed from a library.
Not all course materials are in the form of textbooks, they may be individual scholarly articles that students will need to locate in academic journals available in the libraries.
Group projects are often required so students need to work well with others.
Grades can often be based on only two or three test results, or a major essay/project and a few exam results.
Time management and planning are critical to success. Procrastination can lead to serious academic difficulties.
Failing to meet progression requirements and/or failing two or more courses may result in being asked to withdraw from the program and from the University.