This is the front page of your blog http://smithmarketingblog.wordpress.com/
re: the front page error message
Sorry, but you are looking for something that isn’t here.
By default the front page of your blog displays all posts. The 404 (page not found) error message on the front page of the blog appeared because the Admin of the blog deleted the placeholder Hello World post. http://en.support.wordpress.com/not-found/ As soon as you publish a post, not a page it will disappear. Read the differences between Pages and Posts.