When you are using the WordPress to create new Posts it will usually add the Author Name and the Date on which the post was made.
There are various posts on the internet as to how to remove this.
The most simple method I have found through Editing the Content.PHP file and remove the following text from it.
See the pictures below for easier explanation. If you want to remove the Author name also then there will be another tag above it which will have the Author info, you can also delete that to get rid of the Author name.
One word of caution, if you change the Template of your WordPress site by using another Theme then you might have to repeat this step again.