Authorization c# mvc

Authorization c# mvc

I want to create c# mvc internet application that allows users to edit
their own accounts. I want to have fields such as first name, surname,
date of birth and location.
I'm aware of the built in authorization and the Authorize attribute for
the controllers. I do currently have the default AccountController in the
project.
I'm just not sure what the best way is to extend on the default username
and password properties for each user? Should I store the membership id in
a new class containing the other properties or is there a better way?