Hi,
I’m new and I’m just starting.
I already created a partner account and as I was about to create a development store and put a name to my development store I encountered this error “Store URL is unavailable” and I could not get past this one to create the store.
I’m having the same issue. Would like to have shopify host my domain, but I have to create an account first and make a store name, but the url that I own is already taken by shopify. It seems many others have this problem. Hopefully they will make this less confusing.