The key is finding what works for you. I worked a few different jobs in college and the overlapping theme was that the jobs all had options for me to work outside typical class hours. That was my personal preference- to separate school time from work time. I worked as a tutor and the group I tutored for allowed me to set my own hours. From what I've heard, tutoring is typically very flexible and a good option once you've taken a few classes that you can teach others.
Other friends of mine did the opposite and found work study jobs or jobs from the school that were during school hours that let them do homework when they weren't busy. For example, many students at my school worked at the dining hall in four hour shifts. If they didn't work directly with food, they were permitted to do homework in their down time. That enabled my friends to get their homework done or study while working.
My parting piece of advice is to not be afraid to get rid of hours or shifts once you do start working if you feel overwhelmed and unable to get your schoolwork done. You shouldn't be afraid to say that a certain amount of hours of work is too much if you're struggling.