Joining student activities is fun, and can even help you build professional skills that will enable you to succeed in your career. For example, joining a student government can help you build leadership skills, or joining your school’s newspaper can help build writing and communication skills.
Volunteering and community service are also important parts of student life while in the US. When you volunteer and help out those in need, you feel pride in giving back to your community. Check out websites like idealist.org or volunteermatch.org for opportunities to give back.