We do not recommend this. It is better to delete all your files and reuse the existing site.
If you do choose to delete a site and then create another with the same, we recommend waiting at least fifteen minutes between deleting and creating. If you don't, some parts of our system may get confused and continue to try to access the old (gone) site.
If your site has the wrong short name then you will have to delete it and create another. Short names cannot be changed.