Goldfish eggs tend to be a bit lighter in color than frog eggs and goldfish eggs are spread out whereas frog's eggs tend to be in clumps.
A female goldfish can expel anywhere from(NNN) NNN-NNNNeggs. There's no particular month that they hatch as goldfish tend to breed around Springtime when the water is starting to warm up after the cold Winter. Once the eggs are expelled they are then fertilized by a male and will hatch in about 2-3 days.
Yes there are definitely male and female goldfish.
If you're seeing black colored eggs they would not be goldfish eggs as
fertilized goldfish eggs are usually clear and the unfertilized ones are beige or white in color.
Also goldfish eggs do not float. They stick to wherever they land.