Though some of the multi-day passes give you access to some (all?) of the clubs.
I think you only have to pay to get in at night when there is music/dancing. Since I was there with 3 young kids we didn't get a chance to check it out.
You basically have to walk through CityWalk to get from the parking garages to the theme parks.They stop charging for parking at 6pm, so it's free to get into CityWalk, but you have to pay to get into some of the clubs!!