Properly create and customise a web app using visual studio 2015 C# MVC template
The short answer to what you are trying to do is; let the Identity classes handle Authentication and User management. You can put your User into a Model class of it's own. Then reference that from the ApplicationUser class that comes with MVC.

Another approach would be to extend the ApplicationUser class itself by adding the additional properties for your profile.

As for Business Logic and N-Tier architecture; put all that aside for the time being. The MVC architecture Semantic approach and Entity Framework kind of help to handle that stuff organically.

I would suggest going through the free training at the Microsoft Video Academy website. That should clear things up for you. 
There's also a class specifically for Entity Framework.

As for the class you submitted. It looks fine. You'll probably want to revisit all the annotations learning more about Entity Framework, depending on your use case..

MVC

Identity Resources