Ok, being new, I know you weren't playing with your 'MY Profile' button: dirt with wood in it has constant decomposing fungi of all natures. Usually fungi aren't the issue. It is viruses that do your plant in. Looks like sunburn, watering issues, lack of a dose of garden fertilizer. Squash like being started before June as well - maybe March here in the deep south. Does your plant get ANY shade esp 1100am thru afternoon? Pots are lots hotter than the ground, so get that pot some shade. They also love water, humidity won't support a squash plant. Too much sun will sunburn small plants.
