The convention center is on South Griffin St on the southern edge of downtown Dallas. There is an exit off I-30 directly to the convention center. Check google maps carefully as it can get confusing down there. S. Griffin actually passes under the convention center. It is about 4 blocks south of Commerce.
Since we live about 35 miles north of Dallas we don't go to any RV parks around here. If you look at campgroundreviews.com, there is nothing listed for Dallas. But there is a KOA in Arlington that gets good reviews. I don't know anything about it though.
Traffic moves fast in Dallas area EXCEPT during rush hour, construction, accidents, rain, full moon, daylight savings time, etc.