It does not have to be fancy, just run a piece of TV coax cable from your television input to the outside, using whatever locations and methods work in your specific rig. Leave a few inches exposed, probably near where you have other hookup connections, in the roadside rear of the trailer. Then have a barrel coax connector on the outside few inches, and another piece of coax which will go from the park connector to the one you have installed on the rig. Screw it all together when you get there, and your hookup is complete.
You will need to learn how to use the Auto Tune setup on your television, and that will pick up all the stations your park cable system provides. That needs to be done for each and every park as the stations and locations are different on every cable system. See your television instruction manual for how to do that, each is slightly different.