Just a bit south of Lebanon, there is a state park with excellent campground facilities. That's my home territory- - - - -went to high school in Wilson County Tennessee back in the 1960's, and Cedars of Lebanon state park was a favorite place to watch the "submarine races" on a summer night!
Edit: In addition to the campground, there are cabins available for rent, and a group lodge with kitchen facilities, a meeting room, and dormitory-style sleeping quarters for up to 80 people. That one might be reserved already if there's a big event like the Chevy show nearby, but smaller facilities might be available if reservations can be made soon.
https://tnstateparks.com/parks/cedars-of-lebanonJerry