Main Account

Google Account Settings

Go to the main login page of your Google Account and login.

Click on 'edit your personal info' to change your First Name, Last Name, nickname, Country and Time Zone. Only First, Last names are required fields)

You can also add/remove email addresses associated to your Google account. (Google will send you a verification email if you are adding a new email address to your account).

You can select one of these email addresses as your default/main login address. You can login with any of the various email accounts you have registered. However, it looks like the password will be the same for all.