Newbie and I'm confused about cycling?

[Lorelei]

3 days ago I bought a 180 liter (almost 48 gallons) aquarium. I want it to be a tropical freshwater tank.
It came as a set and included was an external canister filter and a heater. I set the heater to 26 celsius (almost 79 fahrenheit).
I have a bottom layer of aquarium plant fertilizer with gravel on top and five living plants. Water conditioner and Easy Start bacterial combi system was added to the water. Does this sound good so far?
Now I am really confused about the cycling part. I read so many conflicting things on the internet. One place says that you should add a few hardy fish in the beginning to get the cycling started, other places say do not ever add fish until the cycling is complete.
I have a test kit, but the employee at the store said it was useless to test the water within the first few days. I also know that I should add any new fish gradually or it will disturb the cycling. But when do I add the first few fish?
I would like to have Cherry Barbs as the first fish. I read these are hardy enough to withstand the cycling part, is this true? I don't want to torture or kill any of them. When should I add them? How many should I add? As an estimate, when should my tank be done cycling?
Thanks for any advice that you can offer this newbie!