Getting Worried, Fish Arriving Tomorrow

Water readings are GH 180, KH 240,  NO2 0, NO3 40, PH 7.5 and Ammonia .50 and I've got fish arriving tomorrow! I got the tank last week and have used Tap Safe and Tetra Safe Start. I was sure he tank would be ready for the 6 Killifish I ordered but now I'm panicking. Thinking whether or not to do a 25% water change?

I bought 2 little red shrimp this morning and they seem fine?

yep followed the instructions exactly. They are coming by post. It was New Years Eve and I'd been chatting (and drinking  ) with a few of my neighbors, one of them had just set up his fish tank and I got all excited as I have kept all sorts of fish in the past and really enjoyed it. We live in "Sheltered Accommodation" this is permanent separate apartments for the over 55s. It's very nice and secure. Anyway up to a few months ago we were not allowed pets but then the rules were relaxed and we are now allowed some caged pets and small fish tanks. When our little party had finished I was browsing the web looking at Killifish with a mind to maybe getting them in the future but before I knew what I'd done I pressed the buy button, naughty I know  I rushed out the next day to buy a small AquaNano 22 tank. Its very heavily planted and has sand substrate. I bought a Api Test kit with 4 test strips in it, the tap safe and TSS. No test strips left now but plenty of the Api Ammonia test kit. I've got nearly a llitre of standing water which has also had some tap safe added to it for top ups and about 10 litres of standing untreated water in the kitchen which i put there this morning just incase i might need to do a water change.  I know you are going to tell me off and I fully deserve it I should know better! I used to run an aquarium shop about 25 years ago, yes I know a lots changed but the basic Be Patient still applies 

tks I will do tomorrow and tks for the tip on opening my parcel

Hi Fiona, the reason i've got water standing by is that I would never even drink water straight from my tap! It comes out really cloudy, it soon clears once i put it in the fridge and tastes fine then so I figured Id best to put some in a jug for top ups and added the tap safe just to make sure.  Having just read on another post that folk have found that the Api Ammonia test still shows at .50 even on well established tanks and that my NO2 and NO3 readings are fine i'm not so worried now but will keep and eye on the ammonia and be ready for a water change if needed. Thanks for your help tho