One character's decision will lead to the clash that sets the story going as all actions come from that one decision. For example, Frodo decides he will go to the Council of Elrond to decide what to do with the Ring of Power in The Lord of the Rings. That one decision triggers the whole novel. It leads to other decisions - Sam joining Frodo on the quest and so on.
So the decisions your characters make should be pivotal ones and drive the story forward. Your characters will need to face the consequences of their actions or inactions as well.