Once I meet a Father/ Mother of Saint, am I forced to do what they say? And can they influence other people's behavior?

The priest / priestess can give advice, they do not give orders. Likewise, they do not intervene to influence anyone. The sacred and inviolable principle of free will applies. Candomblé respects the decisions of those who are part of religion, of those who are mere observers, of those who only want advice. Everyone's freedom is respected. Do not enlist the help of a priest to condition another person's thinking on your behalf.