I cannot sign in to the German app store

I just moved from America To Germany.I just bought an iPhone SE. I needed to switch to the German App Store and so now that I'm on the German App Store I try to sign in and it says this Apple ID is only valid for purchases in the us App Store you will be switched to the us app store. But I want the German App Store and I want to be able to download stuff please help! Note that I am on a family share.