When you are choosing a personalised URL for your website there is a option to select 'Ask search engines like Google to not list our website' which means it will not be available for anyone unless they type in the exact URL to find your site.
Your website is static page so all visitors will see all the details you have added to the website. However, once guests access the guest area they will only be shown details of the events they have been assigned to on your guestlist - The system uses their email link/address/code to identify them correctly. This means you don't have to add full details of all events to your website as guests can find all additional information when logged in.
You can find more information about our Guest Area here - https://gettingmarried.co.uk/guest-area-user-guide/