You should have your editor orientation document to work through. It will walk you through the main features of the site and the things you need to do to get it set up.
When you are ready, you can remove this post in MANAGE > POSTS. But PLEASE: don't remove this post until you have translated a couple of other real GV posts and added their categories. The site will show errors if there isn't at least one post with the major categories on it, so until you have some posts translated please leave this one here.
To remove this just go to the widgets settings and edit this text box to have your own message to your visitors.