When do you start ganking as a jungler?

Been playing a month, mostly top/jungle, and kinda veered into Zac jungle because I like him. Generally, assuming he's still a viable jungler, when do you gank? I feel like bare minimum waiting until you're 3 is best but I've mostly been focusing on farming until I'm 6, do an objective and then start looking to jump into lanes - but idk if that's the best way to do it.