Q: Whats my firevault Firevault recovery key????

I use FileVault but in my case I turned it on in a previous version of OS X and there was no way to miss seeing the recovery key, even if I selected the option to have Apple store a copy of it. According to the following link it may now be possible that the recovery key is hidden (see item 5): https://support.apple.com/kb/PH18637?locale=en_US&viewlocale=en_US

If you didn't see the recovery key you may want to wait until it has finished encrypting, turn FileVault off, wait until it finishes decrypting and then turn it on again and use the link above to insure that you see the key.

Hello

First it helps if you post the question in the right forum.

I would follow the below link

Use FileVault to encrypt the startup disk on your Mac - Apple Support

You will see a link for "Forgot Password"

Best of luck