I want to call actor blueprint in my c++ character class to simulate particle effect and sound at location of rifle
You can declare a C++ UFunction as BlueprintImplementable meaning that the actual implementation is delegated to a blueprint graph.
What you have to do is create a function inside your character similar to this:
UFUNCTION(BlueprintImplementable, Category = "Shooting") void SpawnParticlesAndSound();
Inside a blueprint class derived from your character class you can now override this function inside the event graph and implement your particle/sound emitter logic.
See this for the documentation:
You must also make sure that the access level of this function is not private.