At Kentucky Horse Park there should be water available at their dumping stations so you will be able to fill any jugs or whatever you use on the way in. Their washrooms and showers are open , large, and clean. Whenever we have done the trip at that time of year in the past we have stayed our first night at Kentucky Horse Park and our second night at the KOA at Forsyth GA. It makes for a bit of a long second day but it's south of Atlanta. To answer your original question, I don't know of many other options on your first day other than a hotel.
