Websites clues? where to start?
I wrote a post about this a little while ago, which also contains some reference links.
Basically, both server and client should have the same set of loaded actors. The server will send all clients the most recent version of all variable marked for replication. All other networking will be done through RPCs, which are functions that are marked that, if called on one computer, will execute on the same object on another computer. Ex: A function marked as a server RPC, when called on a client’s PlayerController, will execute on the server’s copy of that client’s playercontroller. ((The server has a copy of the player controller for each connected client… clients only have their own.))
Of course, you can also use network sockets to a web or cloud server for special functionality. But yeah, don’t even think about using it to communicate between your game server and your game client. That is more for, like, cloud saves or unlockables.
One of our support staff also wrote up a nice guide that runs through the process of setting up a basic multiplayer project in both C++ and Blueprints: https://wiki.unrealengine.com/4_13%2B_Network_Guide
I’d consider that a decent place to start and a great way to have something tangible that you can start to tinker with.
I would add that taking a look at the Unreal Engine Shooter Game source code can be a handy reference at times in figuring out how to do it with Unreal’s native networking functions.
You can also read through exi’s Compendium, it’s perfect for beginners: link