Image via WikipediaAlmost every college and university out there has a student government of some kind. The power and prestige of these organizations varies between schools, as does how they function. In some schools, the elections are nothing more than a popularity contest. At other schools, student government actually has some level of control over the administration.
No matter what kind of reputation your school's student government has, I would recomend getting involved, even if just by attending meetings. You will hear all kinds of rumors about what your Student Government is like, and while a lot of it will be true, some will also be assumptions, opinions or false. It's best to find out for yourself.
No matter what they student government is like, you can still have a role in it, and therefore a role in changing your school. So talk to a current member and find out how you can get involved or learn more.