Q: Where is security section on Apple ID account page?  I want to turn off two-step verification but can't locate the icon.

When you log in to https://appleid.apple.com/ under the account, manage section, the security tab is the very second tab. There should show there that 2-step verification is ON. Tap "edit" in that section and you should see the option to turn 2-step off.

see Frequently asked questions about two-step verification for Apple ID - Apple Support

P.S. You have to disable it through the web account management portal. If you're viewing your account in iTunes or elsewhere, you will not see any tools about 2-step verification.