[Sky]

It basically helps the PHs and nitrites and nitrates balance out so they don't affect your animals and make them sick - which you can test for yourself or have your pet shop do.

I've it done with my fish and axolotl. I've also not cycled a tank with fish and they were fine also, but it's still better not to stress them out if you can avoid it.
With my axie, I had water plants in the tank from the word go. I let it cycle for about a month before one of the plants died and I did a full clean out of the tank, but didn't touch the filter as that is where it's mostly balance out. A week or so later, I got my guy and he was fine. It really appends on the size of tank you have set up, to how long the cycling will take. Mine is 13 gallons/60 litres. I say at two weeks you'd be fine with an axolotl.