MVVM tricky navigation wanted

Hello,

 

 

 I want to find out How can I do this two behaviors but I don't know how neither find it online.

 

 

Q1: (Red arrows) I open the app and the mainview loads immediately the LoginView in the main View I have a button called recovery that loads another view to make the password recovery. From that View I'm able to goback to the main (loginview) again. How can I do this?

 

 Q2: (blue arrows) I want to open a new window without breaking the MVVM pattern. How can I do this?

 

 

I hope that I was clear enough, I'm still trying to learn all of this concept of MVVM and WPF/C# as well.

 

Best regards and many thanks for your time.