When It's Appropriate to Disagree?

i recently started a new job, and i'm curious when it's appropriate to begin disagreeing or expressing a different opinion. How would i know? I haven't had a job in yours. A ahaha, haiahaha. H the one time i went, i had a job an the wase post, i felt that the best way to be at work was deeply passive aggressive. That is, that you should never express your disagreement in a straightforward way. You should rather quietly come and in a kind of behind back sort of way, make your feelings known. And this that was called strategic slappiness, is so routinely violated by people.