2. Learn a non-professional skill.
Use your spare time to master another skill. The spare time in college is enough for you to master a skill, which may become your career. The key is whether you are willing to spend time studying, such as writing, photography, ps, pr, etc. But you must choose what you are interested in, or you will give up in a few days. Interest is the best teacher.
Read for half an hour before going to bed every night. Reading is the most useful thing before going to bed at night, because your brain is clearest at this time, and the content of reading is easy to remember in your brain. I have been insisting on this habit, and I may not see the effect in the short term, but believe me for a long time, you will certainly benefit a lot!