Depends. During the day, only the restaurants and stores are open, so no charge there. In the evening, the bars open after 5PM and start charging cover around 9PM. Some of the restaurants start charging after 9PM too. If you plan on visiting different bars after 9PM, instead of paying a cover at each bar, you can buy a party pass instead.
Citywalk also uses the same parking structure that the parks use, so you will have to pay a parking fee if you're using a car to get there too.
Also, the 2 Park Unlimited Theme Park Ticket give you free access like the party pass does.