Go to the county website…GIS is usually the easiest place to start. Google the name of the county and “GIS parcel viewer” after the county name to find the best sites.
Alternatively you can call the recorder or even the treasurer. This info/phone number is availble by googling the county and “phone number” after it.
With that information you can find the current deed holder, this should be the person/business selling you the land, though it could be newly recorded into their name…therefore not posting on the county systems for multiple weeks in some counties. A call should be able to clear that up if needed…or a signed, notarized, and county stamped (recorder) deed copy from the seller (with recent date).
You will want to check the taxes due (make sure not overdue, ideally paid in full), the current owner (as above), and any other recorded documents (liens, etc.) to be sure the parcel is free of concerns. This can also be verified if closed through title or can be run through a title search service separately.
If you have any questions on how to do this, please feel free to reach out!