ReCaptcha keys are automatically generated keys that you can use. It is usually not needed to edit the key information but if for some reason you lose the key and need to generate a new one, the "Setup/Configuration: ReCaptcha" page is where it can be changed. Just paste them in the fields provided. I didn't get a generated key, nor can I generate a new one. How do I go about getting a new key?
You have to create an account https://www.google.com/recaptcha Personally I find recaptcha annoying! Instead I created a Random Questions brick in my amember forms. My users just need to enter some simple math. Easier and I never get spam or false sign ups!