From my experience not knowing what to do is an excuse people give for lack of execution. While not knowing enough may be a legitimate concern, the state of not knowing can be used to not act at all. People claim they don’t know what to do because they don’t have a degree, because they don’t have a report, or because politics is keeping critical and timely information from them and their department. You should continue to improve and get new information and always work to know more. This requires action, to make the changes to know more.
Doing what you know is how people execute and get things done, not by being in a constant state of focusing on not knowing things. Being in a state of motion is better than not doing anything. When in doubt, act. Action is when you truly have made a decision.