If you want your goldfish to spawn, they first of all need to be old enough. One year may not cut it. They cannot have any predators that will eat the eggs. They need a place to lay the eggs (suspended), the water temperature cannot be too cold.
I had a piece of driftwood in my first pond that they used to attach their eggs to. I was very surprised, after years of ponds to discover that little trick. Once you get this all right, you will have many fry. I had so many one summer the pet shops were buying them from me.