Two factor authentication doesn't use security questions.*
"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" see if at this stage you can still sign up for Two Factor Authentication:
Two-factor authentication for Apple ID --> https://support.apple.com/HT204915
If you cannot resolve the issue by signing up for Two Factor Authentication, "Contact Apple for help with Apple ID account security"; click here --> https://support.apple.com/HT204169
*Two-factor authentication for Apple ID - Apple Support
"When you enroll in two-factor authentication, we keep your old security questions on file for two weeks in case you need to return your account to its previous security settings. After that, they're deleted."