It is better to decide on a few important rules, such as not hurting others and not damaging property, and then to ignore temporarily some things like making noise or clutter. These children respond in the long run to a lot of gentle guidance. Overly cautious children, on the other hand, are watchers. They don't like to make mistakes. Do this when you are ready.
Young children go through four stages as they learn to defend their territory.
The first stage is simply hitting or grabbing to get what they need. The second stage is the use of verbal aggression-words as power. Older preschoolers learn to collect allies. They learn how to gang up on each other. When you need to, set some rules about these actions, but remember your child is handling situations the best she can with limited experience.