Hello. I have purchased a home built in 1938 with hardwood throughout. Two bedrooms have painted white floors and one has brown and cream checker board painted on. I will eventually refinish all of them, but for now, would it be detrimental to lightly sand down the paint to expose wood and then just seal? So paint remains but not solid. I assume I would not really be sanding much wood so I can come back and refinish in a few years. Thanks

Floor paint can have lead in it, so it's not recommended to sand off the paint unless precautions are taken. You may be able to clean it very well and apply a couple of coats of water-based varnish over the floor and have it stick. If one coat sticks, you can add another without much additional preparation and have it last much longer. Test a corner, if it has been waxed, which takes a lot of energy and is seldom done, the finish will peel off with your fingernail when dry.
A homeowner can sand off lead paint without being trained. A floor contractor risks a large fine to sand paint off without checking to be sure that there is no lead in the paint. There may be no lead in the paint, but it should be checked before any sanding.