Lynda is giving you good advice. With fish in an uncycled tank, you'll want to do daily water changes at least until your test kit arrives. Ammonia can build up quickly and hurt the fish. I'd do a minimum of 50% water change daily with the Prime (it makes tap water safe for fish, it doesn't do anything for the cycle) -- make sure you try to match the temp of the tap water as closely to the tank water as you can get it (feel both with your hand).
When the test kit arrives, test your water daily. Any time ammonia and nitrite are over .25, do a water change to get them down. This may mean more than one water change per day. For example, if your ammonia is 1, a 50% will only get it down to .5 which is still toxic, so you'll need to do another 60%+ water change to get it down under .25. This will be going on for some weeks, so be prepared. After ammonia rises and falls, nitrite will start to build, and it'll build fast, so testing and water change are important. Again the process is going to take 3-8 weeks on average.
There's a link in my signature called "new tank with fish;" read it and it'll give you some good info. Good luck.