yes...well at age 5 or so everyone starts kindergarten...and then first to eigth grade is elementary...high school starts at around 14 years old, 9th - 12th grade. at 17 (i am 17 too! you would probably be a junior, or 11th grade. that is, if you turned 17 this schoolyear. if you are already 17 when school started and you turn 18 this year you would probably be a senior, 12th grade.
oh and yeah, after you finish 12 years of school, 9-12 is high school, you can apply to go to college, but by then you are an adult, you get to choose whether you want to go to college or work or whatever you want.
where are you from?