Scroll the iTunes page down to its very bottom. You will see a drop-down box in the extreme lower right of the window. You will not be able to see what that dropdown does, because its label is written in Swahili. But drop it down anyway, and you get to choose your store (and language).
This info is actually in iTunes Help, but it's way at the bottom, after some stuff that looks like the end of the help text. Grrrrr.

