The cURL request for Google profile data was rejected. Update to CB Connenct 6.0.5 if you haven't already then see if issue persists.
Yes the tutorials are out of date and they will not be updated until I have time to update them, which won't be until after GJ is upgraded. The tutorials however are still relevant. A lot of the sceenshots have changed, but the application configuration parameters are all still named the same. The below HybridAuth guide is also still accurate.
hybridauth.sourceforge.net/userguide/IDProvider_info_Google.html
The Callback URL needed for "AUTHORIZED REDIRECT URI" is provided in CB Connect > Parameters > Google > Application.
Please note it can take up to 15 mins for your Google credentials to become active. When configuration your Google credentials please allow for ample time for them to propagate your application to their cached servers (usually takes about 5 mins).
If issue persists then enable debug mode and maximum error reporting in Joomla global configuration and retry to see if any further errors are output. If not check server error log to see if any errors occurred.