There are no RV parks near Fairpark. If there were, they would not be safe to stay in, unless you patrolled around your RV all night with a loaded shotgun.
Just north of Dallas, in Denton, there is Destiny RV Park,. It is located right along Interstate 35E. From there, you can make a short drive over to Medpark Station in south Denton, and ride commuter rail right to Fairpark. You need to study the train schedules, as you make about 2 connections to other trains to get to the game. The train schedules are all coordinated though, so it makes for easy transfers. Best of all, you will not need to drive in the nightmarish traffic to get to and from the game.
Jeff