Yes, you haven't been given any information on the need for a "biofilter" to be established prior to introducing fish. You are in what we call a "Fish-In Cycling Situation" and before we get off on explaining that I suggest that you may urgently need to perform a large water change with good technique: If you have what we call a gravel-cleaning siphon then you use it to siphon out at least 50% of the water into a catch bucket (don't throw out the last of the water.) The gravel needs to get "cleaned" (even if you can't see any sediment) during this process. The return tap water needs to be again treated with the same conditioner you used before (however I'd dose it at 1.5x whatever they tell you) and the return water needs to be roughly temperature matched (your hand is good enough for that.)
Once that is done, your homework is to read 3 of the Beginners Resource Center articles: The Nitrogen Cycle, The Fish-In Cycle and The Fishless Cycle. This will help you ask questions here in your thread. You will need to pick up a good liquid-reagent based test kit (the paper strips are worse than useless, they lead to wrong decisions sometimes.) Most of us like and use the API Freshwater Master Test Kit. Many of us are Dads and Moms who got into this the same way as you, so you'll not be alone and it can be rather fun talking with the members, they're great! We get dozens of cases like yours each month.
~~waterdrop~~