I'm a junior & REALLY want to get recognized by colleges, what can I do to raise my gpa close to 4.0!? Please please help me, I joined band this year, will that help in any way?

^(sorry I wasn't very clear on that, I meant will it help me get recognized by colleges as I know they also look for extracurricular commitment but does that also depend on the time? Or something? Will having joined band help in general?)