When fish lay eggs and are fertilised by the males this is called spawning. In a large area, like a pond, many of the eggs and resulting fry may survive. In a tank most, if not all, will be eaten.
If your expert is correct, the eggs you have will not be goldfish eggs
If they are clear and look like jelly they may very well be snail eggs. They will be found all over plants and in the 'joints' between stems and branches too.
Goldfish usually lay eggs on the underside of wide leaves