You should cycle your tank completely before adding any fish, then add slowly. If the Whisper 60 that you already have was on an established tank then your cycle may be started already, but if there was not a source of ammonia then I would say its not started. You need a source of ammonia to feed the proper bacteria and all of that fun stuff.
You can do this fishless (which I recommend because its the safest for your fishies). If you can find pure ammonia, no colors no scents no additives at all, then use that (around here its impossible to find pure). You add enough ammonia to get your ammonia test to read 3-4ppm. You add enough daily to keep the number in that range. You should see nitrIte after about a week. Eventually your nitrIte will spike and nitrAte will show up. Make sure you are adding enough ammonia to keep your ammonia at 3-4ppm throughout this. When your nitrIte reaches 0 and your ammonia is back at 0 within 24 hours of putting it in, your tank is cycled.
You can also use a large frozen shrimp prawn from the supermarket to do this. Put it in a pantyhose to contain the mess. Its the same process though
If you added bacteria and it was not from BiroSpira or Stability you are probably not getting the right bacteria, this can slow your process so choose wisely grasshopper. Cycle has the wrong bacteria, or it did. I heard that they claim to have fixed this, but I would not count on that right now. If you do use BiroSpira then your tank is essentially cycled within 24 hours and you need to make sure you add fish or ammonia the next day or your money will be wasted.
A cycle will take 4-6 weeks without a product like BiroSpira or the use of established media from another tank. If it happens quicker than that be wary!
You could add a fish each week once the tank is cycled, as long as there is not a mini cycle after adding the new fish. So you would want to test throughout and make sure your tank is keeping up with the bioload. The cycle is a pain in the butt, but well worth the positive health results you get with your fish
Patience is your best friend in this instance!
goodluck