Open a UE4 project that has an object you can get a C++ interface with. For example, you can construct a C++ class Coin that derives from Actor to test out rotations. Override the Coin::Tick() method to apply your rotations from the C++ code. Alternatively, you can call these rotation functions in the Tick event from Blueprints.
In this example, we will rotate an object at a rate of one degree per second by making use of an Actor component. The actual rotation will be the accumulated time since the object was created. To get this value, we'll just call GetWorld()->TimeSeconds.