If you're flying in, I would highly recommend renting a car as Knoxville is a big area and the airport is actually located in Alcoa! The wedding venue is also located outside of town by a few miles.
I have listed a few hotels in Knoxville that aren't too far from Seymour, where the wedding is being held. Seymour itself doesn't have an hotels, at least not listed on Expedia, just AirBNBs. You're more than welcome to go look at those too!