A deleted site in Pressero is not removed from your account, but is moved to the Deleted Sites list and effectively deactivated. The site and all of it's settings do still exist.
Deleted sites will be listed under the Deleted Sites heading on the lefthand menu bar when you are logged into your Pressero account. Editing and saving a site on the Deleted Sites listing will make the site active again and move it back to your Sites list.
Note: Depending on how many sites you have created already in your account, undeleting a site may result in an error message if you have reached your limits for how many sites of each type you can have. Please check this article for more information
on how to check limits on types of sites for your account.