Kareem's old town is called K-Nation. By going to the dream, Josh (said as Kareem), along with 2 other Kareems are there. This means that Tarik was originally from an another town before they all moved together to Kareville.
If you go back to older dream versions of K-Nation, Leslie is actually there. This means she moved to another town before she moved to Kareville.
However, you cannot go to K-Nation anymore because of the Welcome Amiibo Update.