As per I know, you cannot get free gold to pla war commander online on facebook. There are plenty of websites (even YouTube videos) are there in Internet, which claims that they are using software to get free gold points as well as other hacks and cheats, but they are not true. They might hijack your facebook ID or they may send virus to your PC, which will get your important data.
The company behind war commander is huge and they know how to defend their game. The game is popular only because of not availability of cheats or hacks. Don't try finding cheats or hacks for any Facebook Online game, it's just waste of time.