Implenting UserAccounts - username issue


Im trying to use UserAccounts with email/pw login and social logins.

Im looking at the microscope example since its working. When I type Meteor.users.findOne(), it has the username input for the standard ui-login. However this is because the UserAccounts asks (for email sign up) only for email and pw.

How do I then make UserAccounts recognise a need for username as seperate input (or use email as username) and display it on the page? Also same for social login, how to have the username for those sites transplant onto the app?

Sorry if this question may sound silly, Im very new to UserAccounts and Meteor.

Appreciate if someone can guide me or share your experiences.