In WordPress you can easily set private status to different posts or to the whole blog.
To do this go to Settings - Reading in your WordPress admin page. There you'll see the Site Visibility Options which will allow you to configure whether your site will be visible to search engines or not.
To make your blog private, select I would like my blog to be visible only to users I choose – Select this option to create a private blog. If you want others to be able to view your private blog you’ll need to invite them to be a viewer.