Replying to GPA?

yes, i know there are a million threads and even one below this somewhere but idc...

i'm a sophomore in highschool, yeah i know that's kinda early to worry about this stuff but oh well. i am a really smart kid actually, but school just doesn't interest me. i mean i make mostly B's and a couple A's, but i just can't really apply myself in school. i never do homework or listen etc. etc. the things you learn are just so boring, most of it is useless, and i often find myself trying to think of ways the teachers are wrong  and things of that nature. anyways i am just wondering do colleges really take your GPA into consideration THAT much. i think i have like a 3.4 or 3.5 now, which isn't really THAT great...i know i will do really good on my SAT's cause i did really good on PSAT's this year...so yeah how much does GPA count, as well as SAT or ACT scores?