How to make and control user?

Hi, i want to make a game which have create user function, like on Plants vs Zombie (make a user name and the point gain in game will give to that user). And also, can i get login FB to make user too? And combine to one user?
So how can i do it? I'm pretty new to Unity and network, so please help me

 

Controlling your users is generally considered bad form

Back on topic why not check out an existing login system. Both Favebook and Parse have login systems you can drop in and use in Unity.

 

do you have example projects of making login system? i'm still don't imagine how can i made and use in Unity