Honestly. The best thing you can do is take all the fish back to the store and start over when you can dedicate some time to it.
While there are chemicals that make claims to help with your issues, they probably dont work as well as they claim and would still require some amount of input from yourself.
If you are still set on keeping the fish i would look at changing at least 100% of the water over the next 24 hours. Probably 50% change, then 3 more 25% changes a few hours apart. Do another 50% change just before you go into hospital. This will stress the fish, but less so than living in toxic water. Seachem prime claims to neuralise low levels of ammonia and nitrite for a day or so. Some people will tell you it doesnt work, but its better than trying nothing. Dont feed your fish while you arent there to monitor water parameters, turn the lights off to minimise metabolic activity. Put in some bottled bacteria like Dr Tims One and Only, Fluval Cycle or Seachem Stability. This may or not do anything, but is better than doing nothing. Hope there is something left when you get back home.
I really hope someone comes on and tells you im talking rubbish and can advise you differently, because i cant see a way out of this that ends well if you arent able to keep on top of regular water changes until your cycle is established.
You may not have picked on what the nitrogen cycle is. This is a good video on it and why it is important.
https://youtu.be/qMk_SfR0CuU