As someone who worked per diem up to 36 hrs/wk at a time, not consistently, I also strongly recommend against working during medical school.
Unless you are crushing all your classes with ease, have a very lucrative income source, and have absolutely nothing better to do, i.e. research, network, self-care, family, etc. It's not worth the risk of potentially failing out, not matching your desired specialty, or time for recovery.
A regular W-2 isn't worth the hassle, and most other income streams, i.e. sales, social media, gig work, takes a lot of time and energy.
I only worked because I had a lighter course load from having done an SMP, knew I was academically "safe", I was already spending time away school each week, and my job was medically relevant, e.g. "I only went to class to socialize and drink coffee".
I stopped towards the end of M-1 because I picked up extracurriculars (research, leadership, networking) that were more valuable to me than the paycheck. Time is the most precious resource you have in medical school.
I also tutored with the school and would recommend that over any other work. You can easily adjust the hours as needed and it'll help you solidify the material.