Authorized_keys are important files which has the information of public keys for public key authentication. By default location is ~/. ssh/authorized_keys.

Where is my Authorized_keys file?

By default the file is located at ~/. ssh/authorized_keys .

Is Authorized_keys a file or directory?

ssh/authorized_keys: No such file or directory. ~/. ssh/authorized_keys are keys of other computers that you connected to/trust, not your own key.