Generic but nonetheless true (at least to me 
) answer: Game-engine are complicated piece of software, and even if the coding workflow is somehow simplified in Unreal Engine, i would strongly recommend to start playing around with Visual Studio community and maybe make some console programs. There’s a lot of great C++ tutorial out there.
With a bit of dedication i would suggest taking a couple weeks to get at least solid theoretical foundation before engaging in UE4 C++.