Learning how to manage your time is an essential life skill that becomes more refined the busier your schedule gets. If you're taking lots of classes and getting involved in clubs and organizations that interest you outside the classroom it's likely that you're finding out how difficult it can be to juggle lots of things at once, which is an important thing to learn.
Time management can be as simple as keeping a daily planner. If you know you have a big test, don't wait until the night before to begin studying. Learning how to manage your time is a skill you get better at the more responsibilities you take on. The benefits of being good at time management carry over to your performance in the classroom, as well.
In college you take courses to see what you're good at and what may have career potential for you years down the road. However, you can also learn just as much about yourself by taking on leadership roles outside the classroom. For example, if you like watching basketball and organizing things, one way to combine both interests (and scope out future career potential) would be to volunteer to be the basketball team's manager (or assistant manager).
At any rate, joining clubs and organizations that interest you can be eye-opening. How better to test run potential careers (or aspects of a career) than to get involved in a low-pressure setting while still in college?
Students join clubs for all kinds of reasons, but one of the biggest reasons has got to be socializing with people who have the same interests. According to Gateway Community College, "Your extracurricular activities revel a great deal about you, such as what your interests are, your priorities, what you value and how you maintain long-term commitment." If you want to meet other people who have the same interests as you, consider joining a club or organization that has a mission you care about, or founding a club based on a topic or sport you want to have a presence on campus.
Sure, joining clubs and participating in activities is really enjoyable, but you should never take on more than you can handle. Before over-extending yourself, always think about your courseload and whether or not you can reasonably afford to join a new group. College is about earning the degree, after all.