Turn off two step verification

There is no way to turn off 2 factor authentication once it has been enabled for 2 weeks. If you really mean legacy 2 step verification you can turn that off→Frequently asked questions about two-step verification for Apple ID - Apple Support, but note that it will automatically convert to 2 factor authentication if you update to iOS 11 or later.

If you turn off 2 factor authentication many secure features of iOS will stop working, such as the Wallet app and password fill.

Apple hasn't used two-step verification in a long time. Do you perhaps mean Two-Factor Authentication?

Two-factor authentication for Apple ID - Apple Support

If you just set up a new Apple ID, you can't turn it off. If you enabled it within the last 14 days on an existing Apple ID, look for the enrollment confirmation email. You should find a link there to turn it back off. Once the 14 days have passed, however, it's permanent.