So, I was looking at Panpour on Serebii to see where to get it in White. Then I noticed something.
It needs a Water Stone to evlolve.
I was like," Okay. So, where do I get the magical stone of wateriness?" I looked it up and saw it was only in Black City. I looked up White Forest to see if it was true, but its not. I think.

It says that you can get it if you have like 70 characters or something? It dosen't make sense to me. Can someone help me?

You can find a person in Castelia City who gives one to you. He's on one of the docks, and he'll give you the option of either Leaf, Fire, or Water Stones. Hope this helps.

As for the White Forest things, they'll just pop up randomly. I got a lot of Repeat Balls that way, and even a Leaf Stone.