Getting into college is not based on one thing. Things like your grades, SAT scores, extracurricular activities and volunteer work are the most common things looked at. Everything is looked at together. You don't have to have participated in extracurricular activities. It does help though.
You can still get into college even if you do not really participate in co-curricular activities. However, for some institutions, they are compulsory while it is voluntary for others. These activities do leave an experience that is lifelong in your schooling days.