You can review and edit basic account information in Account settings.
You can edit your Account settings by clicking on your Gravatar (avatar) in the upper right-hand corner of your admin bar:
From the Profile page, click the Account tab:
Username: Your WordPress.com username. You can change your username by clicking the “Change” link next to it. Your WordPress.com username will display next to any posts you make in the WordPress.com forums.
Email Address: Required. You may change this, but note that email addresses cannot be shared among accounts. That is, one email address cannot be registered with multiple accounts. You will need to confirm by email when changing your email address.
Note: Although your email address will not be displayed publicly on WordPress.com, when you comment on any site while logged into your WordPress.com account, the e-mail address will be visible to the site’s owner/administrator.
Primary Blog: Choose which blog you want to be your primary blog. If you only have one blog there will be no dropdown.
Web Address: Not required. The full URL of your main website or blog. Your Public Display Name will link to the URL you have entered here when you leave comments on WordPress.com sites.
Fun: It wouldn’t be any fun if we told you what this does. Just try it out for yourself and see what happens.
Instant Post Feedback: Check this option if you want to see instant post feedback when you publish new posts.
Remember: If you make any changes to your Account settings, be sure to click the Save Changes button at the bottom!