Fortnite Paragon Quake; How to do MP games with UE4?

Fortnite Paragon Quake; How to do MP games with UE4?

I am new to the engine. I noticed there are games that appear to be made by unreal company themselves.

I am interested in learning the ways they did this; keeping track of player’s individual level but also running a game instance.

I am interested in their ways of doing things because I see it as “official the best way to do it” because the company that made UE4 made those games?