Without having any more specific information (which you need not share) Duluth is a fairly large city for Minnesota, unless you have a specific specialist need or some insurance need, you should be able to find the care you need for most common needs and have a good number of providers to find a professional that meets your care needs. At a worst case scenario, both the twin cities and Rochester (Mayo Clinic) are about 3 hours away, and that should exhaust even the most rare specialists.

They've got two main hospitals, Essentia Health - St Mary's and St Luke's. They were pretty good last I checked, which admittedly was like a decade ago at this point. But even if they aren't you've got Mayo a few hours away like the other guy said.