There are so many free sites that offer free blog. Two most popular and trustable blog sites are www.blogger.com and www.wordpress.com. You do not have to worry about security of your blog content s. You can download the free templates or themes and it is very easy to manipulate the widgets. This two free blog sites requires less code skill and it is recommended for the beginner.
You can visit this post if you ready to start blogging with blogger.com.
How to Start Blogging with Blogspot