UE4 Networking and synchronization

Hey guys,

I try to synchronize my game for a long time, but I didnt find out how.
I dont find something on the internet what can help me for my problem.
Can somebody give me an example how I can synchronize my two clients?
For example I have a lightsource. I want to switch it on and off. But I only see it when my server is doing this action, but I don´t see something if my client is doing it.

Other synchronization problem:
I have a 3d blendspace. If I use a normal 2D blendspace my characters move with animations on both clients, but if I use 3d blendspace I only see my own animations, but not from another character. How can I synchronize my 3d blendspace to see animations on all characters?

I hope somebody can help me! I really need to know this.