I assume by cycle we're talking about ammonia. Just as JW said.
To know a pond is ready for ammonia you have to first measure some ammonia. When the level goes back to zero you know bacteria is established. No need to add bacteria, mother nature provides plenty for free.
Instead of adding fish you can add plain ammonia from the drug store as long as there's no fish. This ammonia is the exact same stuff the bacteria eat. You can't really add too much, provided no fish. Bacteria will convert it in about a week if the condition JW said are met.
The downside to adding a few goldfish is they probably won't produce enough ammonia to be measured. Without measuring ammonia and then a decline there's no way to tell if the bacteria are ready. You can still add ammonia with fish if you measure and understand how ammonia relates to water temp, pH and the length of time ammonia levels are maintained. Cooler the water the less
toxic the ammonia.
That's a lot of over thinking for most water gardens. Just adding some small fish, not feeding a lot, and when water is cool is commonly done without any problem. Ammonia bacteria reproduce fast and so you may never measure any ammonia.
The whole forcing bacteria growth before fish are added is used by people planning to buy a truck load of full grown Koi for a new pond. In that case a week can be too long to wait for the bacteria. But for most water gardens...not an issue. Just measure ammonia to be sure. If it gets to dangerous levels based on water temp and pH you can do temporary treatment and/or water changes.