Help sending different info across network

Hi everyone.
Sorry if this issue has been delt with in the past but I couldn't find it in the forums.
Basically I want to be able to send different information to all the players in the game.
For example if a player pushes a button to shoot a canon/bullet have that player instantiate a rigidbody bullet with force, while sending info to the other clients to make their version of that player instantiate a fake bullet which would be just a mesh with no colliders. So the server only calculates the damage from that one bullet.
I've managed to successfully set up an environment where players can spawn in as a cube but having trouble making them shoot. And