Quitting army rotc scholarship after first year?

i am a freshman in college right now, and i have the rotc scholarship so they have been paying for my tuition. i want to get off the scholarship for next year, so i am thinking about quitting rotc by the time my freshman year ends. will i have to pay back the tuition/stipend even tho i quit after freshman year? will i have service obligations, like active duty? can i re-contract for rotc my junior year if i quit this year?