For me it looks like the compiler can’t say which of those functions you want to use. So you need to do a clariication there for example:
UGameplayStatics::SpawnSoundAttached(DamageType->DamageSound, FirstPersonCameraComponent, NAME_None, FVector(5,0,0),EAttachLocation::KeepRelativeOffset );
When you do that, it should compile perfectly fine!