To my knowledge, there isn't one.Does anybody know where the wifi room even is? In the overworld? Everybody else seems to know and I feel like it should be immediately obvious but I can't find it.
You now access Wifi and trading through the Player Search System. Press L or R until it pops up on your lower screen. The Wifi Logo in the upper right can then be pressed to link you into the internet, where thousands of trainers will then appear in the "Passerby" list for you to interact with. Friends are people you have Friended who are online, and Acquaintances are those you have traded or battled with in the past, but not friended.