She’ll be handing you the divorce papers within a year 
- I’ve lost three girlfriends to UDK and iOS development 
If only a partner could give you as much satisfaction as your little world you create in your game engine.
There are no cheat sheets for anything in UE4, it’s all brand new and still under documentation, so you’ve come in at the right time to learn with us and make great games of the future with this amazing team at Epic Games.
As for login screens and such, that section is still under documented and will be updated soon, (slate UI)
Dave