This is a blog post. To edit it, browse to the slug 'first_post' in the Control Panel, then click on the Content tab. You can also see it along with other posts in the "Posts & subpages" tab of the blog in the Control Panel.
You can insert photos into a post and embed content.
This copy is displayed after the flip - which means you have to click on the "read more" link to read it. This format allows people to scan multiple blog posts on your blog's main page rather than being overwhelmed by one long post.