IPhone 7 Plus camera broken?

So I dropped my phone and one side of the duel camera broke, how much does it cost to get this fixed? I'm sure Apple has it on their website somewhere but I can't find it.

How do I use Google Authenticator on a new phone?

Back then, I would use Google Authenticator on my iPhone to get the 2FA pins for apps and services such as Snapchat login.

Recently I have switched to a new Samsung Galaxy S8 and have installed Google Authenticator on it.

However, when I open the app, I do not have all of the accounts that I synced before and therefore I can't login to those apps or services like Snapchat that require that 2FA pin.

How am I supposed to get back all of my codes to work on my Samsung Galaxy S8 just as it did before on my iPhone?