Since the Home page is the root page in your page tree it cannot be deleted. Otherwise, all the pages under it would be deleted as well similar to the folder structure of a computer's files.
If you have a current sub-page that you would rather see as the Home page what you can do is drag and drop that page's wireframe onto the Home page in the page tree and then rename the Home page to have the same name. After that, you can delete your original page with no content or rename it and start a new wireframe on it. One thing to remember is that you may need to update your navigations to match the change.
Another solution, which may save some additional time, is to just have a single page underneath the Home page and have that be the new root where all the other pages are attached to.