There is parking near the convention center. Some pay up close. I dont like to pay so park away and walk. OK if not too hot or raining. There are free shuttle buses that run a variety of routes all centering around the bus tent at the center. You can pick up a schedule on some of the buses or at the bus tent at the convention center. There is a good Paducah booth at the entrance to the center and the assistors usually wore red coats. They will have all kinds of helpful info.
Hancocks of Paducah is another place to park and ride. Many of the buses go there.
But best is to park somewhere around the convention center to save valuable time. You can then see the show and maybe take a shuttle to give a rest to your feet and see some other part like Eleanor Burns, the Rotary show or such.