Do you know C++ ?
Do you know how Unreal assings things? (UPROPERTY,UFUNCTION,etc)
There are things that are better to be done in the editor, like creating animation curves/timelines,
setting up an actor with skeletal meshes, scene components, colliders, etc etc)…that setup is better to be done in the EDITOR and then you access from C++ because if you want to make an animation curve a pure coding you must enter each keyframe with tangents, etc… doing it via code is just insane.
Then understand different actors/components to know how to invoke in C++.
When you use a blueprint node, if you hover it with the mouse it will hint you the origin of the node to be used in C++.
I will show you some examples:

you can see that getWorldDeltaSeconds comes from gameplaystatics
then in your IDE you type gameplaystatics and it will suggest and you continue:

if your ide dont add the include for you you must do it:
#include "Kismet/GameplayStatics.h"
another example:

you see it uses Kismet Math Library and has 5 inputs and 1 output then
type something like kismat and if you IDE is good enoug it would suggest:

after UKismetMathLibrary you add :: and will suggest all the functions
and type: mapclamp and will suggest:

then:
objects in unreal start with U so you want to set a morph target weight
the object is a skeletal mesh, right? ok… you can google USkeletalMesh and
unreal documentation will popup with the info…
is a skeletal mesh component? lets type uskeletal and see what happens:

ok there is it…lets find out morph:

ok there is it

this is what it asks then:

Hope it helps!