Empty Site
Sometimes you may have a blog that you’ve worked on for a while, but you want to start over. If you’d like a clean slate, you have two options.
Empty your site
If you want a fresh start on your WordPress.com site, you can delete all of your content from your site and still keep your current WordPress.com address (such as yourgroovysite.wordpress.com). Here’s how to do it:
Create a new blog
Your other option is to create a brand new blog, with a new WordPress.com address, under your existing WordPress.com account. There is no limit on how many blogs a user can have on WordPress.com.