I echo what @GreenDuck12 @ReturnToMed @Tenk and @throwaway1000000 said about investing. Money now is less work later.
I'll go against what @wxman about credit only because in certain cities you're FICO score is required to rent an apartment, no FICO no place to live (major cities: NYC, Chicago, Boston, LA, Seattle, etc) or you'll need someone to co-sign the lease.
I personally am lucky to have no debt from school. To add to the above: in residency you'll have less time so prioritize your personal needs and convenience. For me these are: living close to the hospital, cleaning lady 1-2x a month, good bed, black out curtains, gadgets that make my life easier/better (air fryer, rice cooker, back massager), costco & amazon prime memberships, using delivery services to save me time.
Make your life easier for you, value your time.