Drupal has a built-in blog module so the first thing you will need to do is to enable the blog module.
The steps to enable blog module is very easy:
. Click administrator
. Click module and look for "blog" and click on enable
Once the blog module is enabled then you will see under "create content" will have a link for "blog entry" click on that to create a blog and just type away.
After you create the blog entry it will show under "Recent blog posts" if you have it enable in the "block"