There are typically severals ways to turn Bitcoin into cash instantly, this are payment made easy on blockchain or crypto apps that enables users to transfer instant bitcoin to their various local accounts or dollars wallet.
It is impossible for someone to do something without understanding what is being done. Someone who wants to be directly involved with Bitcoin must already understand how to convert Bitcoin into fiat. You have to do KYC on a centralized exchange, many crypto users use this service as traders and Investors are very familiar with it.
Bitcoin ATM are not yet widely available in public places in some countries, I think this option can still be replaced by transferring from a Bitcoin wallet or at a centralized exchange.