If your ammonia = 0, nitrite = 0, and nitrate = 0, I don't think you "have to" perform some big water change. You could perform a partial water change if you want to, why not. If nitrate is more than 0, sure you can perform a water change to remove the nitrate. Now, you're probably thinking of adding fish to your tank, since it's cycled. But don't be fooled: just because the tank seems cycled does not mean it will stay so after you add many fish at once. When you add many fish at once, ammonia and/or nitrite can suddenly go up. So stock your tank GRADUALLY, adding one or two fish every week or so. Continue this until the tank is stocked to the level you want it to be (but of course don't overstock!). This way, the beneficial bacteria have the time to develop and you don't risk sudden ammonia or nitrite spikes that could kill your fish.
I have heard with the ammonia fishless cyclying, which is adding pure ammonia to the tank, when your finished, you should do a 30-50% water change. Isabella is right with the stocking, you want to stock gradually. You should also try to get some hardier fish,just in case a problem develops whenthe fih are added. Some good canidates are zebra danios, black neon tetras, all livebearers, convict cichlids, oscars, and goldfish if you have room. For the schooling fish, you could add six safely, but with the cichlids and goldfish, you should add one or two at a time. After that, as long as you have room, you've done good research, and the fish are compatible, you can add any fish you would like, but you should follow the same rules for stocking.
A partial water change is ok, If you vacuum the gravel only vacuum half of it each water change. Remember only a partial water change at no time do you want to change all of it.
As Isabella and Skadunkadunk cautioned add your fish a few each week until you get what you want in there. Research your fish carefully before buying. Making lists of what you want is part of the fun of starting a new tank
Skadunkadunk 's list is a good starter to research except the Goldfish. Goldfish are coldwater fish(meaning no heater) not tropical. they also need more room than tropical.
The only fishless cycle I ever did that was not done with Bio-Spira was done with pure ammonia and it works great. You do a 30% water change at the end and you are good to go. It was the best and cleanest cycle I did without the benefit or Bio-Spira. It took very little time because I did not have to wait for the other stuff to turn to ammonia so that step was bypassed. If I could not get Bio-Spira I would not hesitate to do another one this way.
I did however only have the one fish to add to the tank when the cycle was complete so I agree that the cycle should not be crowded at first.