Plone's built in News Items and News folder (and the collection that shows most recent news items) and the news portlet are "ready made" for blogging.
Take a look at Blog addon for Plone 5? - #4 by tkimnguyen
This describes how you can make a blog out of the news items that come with Plone.
http://www.uwosh.edu/ploneprojects/docs/how-tos/how-to-make-a-simple-blog47
Or, you could simply rename your site's News folder to "Blog".
This is an example of such a "simple blog": Blog — Design Intervention Systems