The good news is looking at the above downloaded DSC_9506.jpg file at 1:1 Zoom View there is no moire. The moire in the boy's blue shirt at less than 1:1 Zoom View is due to interpolation artifacts created in the resized (Fit, Fill, etc.) LR preview. This will not show up in print copies. To remove the moire in screen viewed images Export the original file with resize more suitable for typical screen resolution such as 2048 Long Edge with Screen Standard Output Sharpening.
(Click on image to see full-size.)
The moire may also appear in print copies. To eliminate it in both print and screen viewed images use the Adjustment Brush and apply Sharpening -55 or higher as required to remove it.