There is no size requirement for a goldfish to be mature enough to breed. The reason I say this is because so very many goldfish are so badly housed and treated that they may become fully mature but only a couple of inches long. Goldfish can usually breed within a year from hatching if they are well looked after.
Goldfish do lay eggs. The eggs will attach to something in the tank or bowl until they hatch.
when you get it a mate.
Goldfish are egg layers
Yes. Laying eggs is how they reproduce.
Yes.
yes
Yes.
yes they can!
Fish lay eggs.
goldfish need to lay eggs. Because if they don't no goldfish would be alive and would not be any more so they would become gone forever.
Of course! Goldfish reproduce sexually not asexually
If it is as old as a goldfish that can, it can.