As a fellow broke college kid, I understand where you are coming from. I work two jobs part-time: CareerVillage and Abercrombie. (However, if you can avoid it don't work two jobs. I'm lucky because my jobs are pretty accommodating to my schedule. This rarely happens when you work two jobs.) But it us totally is doable to work part time and be in college.
Make college your first priority-Tell your manager, "I'm a college student, I can only work around these times Insert the times when you are free. At Abercrombie we have a employee website where we are available to change our availability by logging into our own accounts. Also, if need to work change your work hours or take time off for whatever ever reason, let your managers know ahead of time ASAP. Most managers will understand and will be accommodating (especially if you have an on campus job.)
Manage your time This is pretty obvious but there are a lot of things that go into this. Use tools like Google calendar, your phone's calendar or an actual physical planner to help budget your time. For example, l do social media for CareerVillage. I will knock that out in the morning during my gap period, I queue up all their social media ahead of time. Then when my gap is over, I will go back to class. After classes are over, I'll spend some time studying sometimes its a lot, sometimes its not a lot. I will work night shifts ( on Thursdays and Fridays) at Abercrombie if they assign me them. Also I work on the weekends I open up my availability to work whatever shift I can at Abercrombie( sometimes its morning, afternoon, or night,) they let me know on my schedule they give to me each week. So ask yourself, "how much of my free time am I going to dedicate to my studies, work, and my personal/social life?" Don't overload yourself with school and work ( it doesn't end well I've had to pull several all nighters before, its not fun.) Find the right balance.
Sometimes you have to sacrifice your social life. -I've remember getting invited to some parties on a Friday night and I couldn't make it due to work. Its ok. There's always going to be another party. Sometimes you can make it, sometimes you can't. Its not the end of the world. I do recommend you still maintain your social life. Don't be buried in your work and school, do some things you like so you don't go insane haha.
Work the early morning shifts or the super late shifts. - Look sometimes you're only free in the early morning or at night. It sucks waking up super early. It sucks working super late. Most people hate these shifts and don't want them so if you're free at those times see if you can take them, they are available. Take them sometimes and put some extra money in your pockets.
I hope this was helpful! Feel free to reach out if you have anymore questions about managing you time let me know. Also, if you need help figuring how to get a part time job or how to navigate the crazy world of retail let me know. More than happy to help! Good luck!