If your site is brand new, it will need a domain name to be registered. SeaSharp will guide you through this process as well as selecting a hosting package. The annual registration cost for a domain is typically $10. Hosting packages should cost no more than $5 per month. Many hosting providers will try to upsell you with unecessary add-ons.
Once the actual design and construction starts, the site pages will be published in a temporary location that only you will have access to, so that you may follow its progress (and advise or critique as we go along).