You definitely want to do the prescribed water change, since this appears to be a fish-in cycle.
You may have added a few fish too many for the cycle, but with sufficiently large and frequent water changes, you should still be fine. (A word of warning, the neons may be a bit sensitive, so extra water changes may be in order to save them during this period.)
You are in a fish-in cycle. Have a read through the fish-in cycle thread (link is in my sig). It will most definitely be of value to you. If you see the ammonia AND/OR the nitrite reading at anything other than zero, you need to do a sufficiently large water change to lower it. Plan on doing a 50% water change daily for a while. Eventually you will be able to stretch that out to every two days, then before you know it the changes will be once a week, and that's when you are fully cycled.
The best thing you have done is come here, and purchased a test kit. Test often, and be prepared to change a large amount of water for the sake of your fish. Also, do not fear that the water changes are stressing your fish - they really don't - and the toxins in the water (ammonia and nitrite) are far more stressful and dangerous.