One of the most useful tools I've found is Soilweb
https://casoilresource.lawr.ucdavis.edu/gmap/.
You can find your location on the map and click the associated soil polygon, and it'll come up with a TON of information, some more esoteric than others. The most useful thing I've found is by clicking the "description" link. If you scroll down to "
Use and Vegetation," it
should provide some insight into native vegetation.
Many state conservation agencies, and university extension programs, can provide insight on native vegetation, and may even be able to help you source native plant nurseries. If you have a college or university nearby (within an hour), often someone in their biology, environmental science, or similar department can help field any questions, or can send you to the right person.
Good luck!