Should be
OurParticleSystem = CreateDefaultSubobject<UParticleSystemComponent>(TEXT("MovementParticles"));
and you include this:
#include "Particles/ParticleSystemComponent.h"
Should be
OurParticleSystem = CreateDefaultSubobject<UParticleSystemComponent>(TEXT("MovementParticles"));
and you include this:
#include "Particles/ParticleSystemComponent.h"