Usually there are some bugs because we wet the substrate and humidity is high, but they are not harmful for your sulcata.
And there should be no mold if you have boiled the coco peat prior to using. But now I wonder, do you buy the big sized coco chip or the sand like coco substrate? Coco peat is the substrate we prefer, with the small particles like sands as it will hold moisture better compares to the bigger chips.