Making a Array for Vector Locations for a object in C++

You have problem with your design. Wrong syntax also wrong assignments. You are assigning nulls to string. Lets not go far away from your design. Generally shields designed like up right left down, 1 thing you can do is :

USTRUCT()
 struct MyShieldQuadrants
 {
    UPROPERTY(EditAnywhere)
    const FVector UPPER_BLOCK_LOCATION = FVector(60.0f, -25.0f, -10.0f); ;

    UPROPERTY(EditAnywhere)
    const FVector LEFT_BLOCK_LOCATION = FVector(60.0f, 16.0f, -10.0f);;

    UPROPERTY(EditAnywhere)
    const FVector RIGHT_BLOCK_LOCATION = FVector(60.0f, 16.0f, -80.0f);;

    UPROPERTY(EditAnywhere)
    const FVector DOWN_BLOCK_LOCATION = FVector(60.0f, -25.0f, -80.0f);;
 
     UPROPERTY()
         FVector CurrentShieldLocation;  //current shield location
 
     void ShieldQuadrants()
     {
         CurrentShieldLocation = DOWN_BLOCK_LOCATION;
     }

     void ChangeShieldLocation(int value)
     {
         switch (value)
         {
              case 0:
                    CurrentShieldLocation = UPPER_BLOCK_LOCATION;
                    break;
              case 1:
                    CurrentShieldLocation = LEFT_BLOCK_LOCATION;
                    break;
              // so on and so on.
         }
     }
 };

I would definetely write a OffHandComponent to manage those. Just have a look. I hope above code will get you somewhere.