Question about setting up new site for existing domain

I am setting up a new site and will be switching the domain to this new WP site when I've finished it. However I was asked for my old domain when putting my new order in - and now it seems as if it keeps looking for that domain. First - what is the name of my current test/site so I can browse online? and how do I go about creating a new site that I can test and route domain to when the design is final? it now asks me to set up my email as '[email protected]' - that is not possible yet... how do I move forward?