If you want to personalize your blog by changing the username from admin to something that represents you, following are the directions:
Go to your Dashboard, scroll down to the Users panel, which is on the left-hand side, and select Your Profile. On the Profile page, insert your desired new public username in the field that says “Nickname (required).” In the field directly below that, which reads “Display name publicly as,” select from the drop-down how you want your name cited on your blog (your new username). There is no need to save your settings prior to doing this; the drop-down menu will automatically populate with your new username, which you entered in the Nickname field. Click on the “Update Profile” button at the bottom of the screen. Your new public username is now changed.