Welcome to the foruns and your first trip in your DP. The shortest is I-75 to Macon and then 129 and 441 BUT 441 through the NP in a 40' DP on your first trip worries me. Not knowing what you've driven before and if you are pulling a car I would suggest: Hitting Atlanta at a non rush hour and going straight through on I-75 all the way to Knoxville and then I-40 east to 66 and then south to Gatlinburg. After going to Newfound Gap in a car you will have a better idea if you want to use 441 south back to Fla.