Directv or Dish for that matter are not too helpful with RV set-ups. More than likely your current sat dish mounted on your RV roof will only receive video content from sat 101. Although we don't know receiver model just crank up dish and connect incoming sat coax to rear of receiver. Power on receiver and step through set-up process of pointing your rooftop dish to sat 101.
Doing this at home where you can see how your residential dish is pointed will help get you on track faster. Choose your type of sat dish (18" round) and peg sat meter preferably in the 90 percent range. The process isn't overly difficult just takes some practice to master. Refer to pointing coordinates on receiver for location you are setting up satellite, helps to be as level as possible.