Balancing Life & Health

Hi everyone! I am a fresh-out-of-high-school college student who works part time at a grocery store. As a freshman in college and 18 year old girl, it is easy to let yourself go. I see it happen all the time (not that there's anything wrong with that), but that's something I'd like to avoid for myself. I find it hard to have time for myself nowadays, when I am not in class or at work I am usually doing homework. Does anyone here have tips on managing time to allow fitness hours? I want to get in the habit of working out every day, but it is difficult. I do not need to go to a gym, I am perfectly fine with home routines. I eat very healthy, am 5'5" and 120 pouds. Also, if you have any exersice tips that'd be great too. I want to tone my stomach, slim down my hips/sides and build my arm strength!