How do you get free gold in world of tanks

You simply can't. It has to be earned or paid for like everyone else.

The sites and software which claim to give you free gold are fake. They may actually download a keylogger onto your computer to steal your password. Sometimes they contain spyware, malware or browser hijackers.
These malicious people will also make money from doing so by getting you to complete a survey or forcing you to see adverts.

These so-called "gaming credit generators" are just a way to prey on your vulnerabilities for profit or personal gain.

Sometimes gaming companies will set up fake "free credits" websites as a sting trap to find which players are seeking to cheat in the game, so they can ban them.