Making new friends, finding people with common interests, and developing interpersonal communication skills are only three of many reasons to join an activity in high school.
Many students who apply to college have similar grades, similar GPAs, and/or similar rankings. Being a member of a team or an active member of a club or organization may go a long way to distinguish one's self from others. It can also show initiative, energy and leadership.
First, by talking to your counselor or teachers, find out if a similar group exists. If not, talk to the principal to determine if such a new group can be formed. Be prepared to find a teacher or other approved staff member who will be willing to serve as a coach or moderator.