Is there a way to go to the city in Animal Crossing wild worl?

There are a number of ways.

The first requires the internet. First get a friend code and ask your friend to get one to. Add each others to each others friend code list and then one of you open the gate. Then the other can walk in to your gate after talking to the dog.

The second requires a DS (Normal, Lite or i). Select DS suitcase by talking to the right hand side dog (Under "I want to go out" and then DS Suitcase). Then connect your DS (together with the wii) (Use the DS download and Play Feature). You should see a screen either telling you you've done it correctly or not. If not repeat and maybe try turning the DS on first. You are then in the DS ready to visit the other town. Take your DS to your Friends house/near their wii and select DS Suitcase from the first screen that appears (With Rover). Download your self and then you are in. Repeat to leave again and rejoin your current town for saving.