Whenever you get a new router or move somewhere, change the WiFi access point name and password. Set it to the same line you used previously. That way all your devices will connect to it without changing anything.
Use a new unique name and password. Never keep the one that is printed on the back of the router. You can make the password easier to share by making it a few words and numbers. Still very strong, but much easier to say aloud to someone.
The Wii u was better (when the game developer used it correctly), it was a separate screen that showed different content. It was more like a DS.
Some of the games in Nintendo land were excellent local multiplayer games that will never get replicated again. They made great use of the second screen concepts.