How to load page in application.hbs?

I have to work with ember.js only in front-end for some website and my friend asked me to load a connexion page then a home page with a navbar etc... My problem is about and I don't really understand because when I my next home page, connexion is still here... I don't know what instruction write in application.hbs in order to load Connexion.hbs then index.hbs with navbar... Can someone help and explain me ?

I just want to load connexion.hbs when I load my website, then I click on "sign in" I want to load another page with a navbar (I already have this code, thanks bootstrap) and home page. I just need some link between my pages.

Thanks !