IMHO....all good answers, What ever camera you choose, it should have manual controls and a working light meter. It may or may not have autofocus or shutter-priority or aperture-priority or all Program mode,
It should have a "standard" lens ( Focal length of anywhere from 48mm to 50mm # f1/8).That being said, best to find a used camera shop, or camera show in some areas, and look around, ask questions, pick it up and handle it. How does it feel in your hands? Are the controls easy to get to and do they move easily? In the event later that you want a different lens, ask about lens availability.
For film, the Pentax k1000 was a workhorse for many, as were the Canon AE-1, The Nikon FM or FM2. I dtill ude sn Olympud OM-1 purchased in 1974. They have good lenses, and both good bodies and lenses can be had affordably. Make sure they take newer non-mercury batteries (or they can be found easily)
Except for the specific cameras mentioned, the same questions should apply to digital. although, the initial cost factor is higher than film