"If you forgot the answers to your Apple ID security questions" click here --> https://support.apple.com/HT201485
If you see the message "not sufficient information" here are two methods that are relatively similar for possibly recovering from "not sufficient information" by signing up for Two Factor Authentication at this stage. See these posts by Community Specialists:
click here --> https://discussions.apple.com/thread/252885215?answerId=255425124022#255425124022
and here --> https://discussions.apple.com/thread/253011979?answerId=255657543022#255657543022
Alternatively "Contact Apple for help with Apple ID account security", click here --> https://support.apple.com/HT204169