Just take your time and wait for things to settle in....... If your KH is low, try a lttle Baking Soda every other day. Check the KH several hours afterwards........It will bring it up....
Get some more test kits when you can. I prefer Salifert, but there are others brands. API for one a bit cheaper and easier to test with for some applications....... Calcium, and Magnesium, would be the next kits to add, maybe Phosphates too........ Along with a Refactometer, and these basic testing kits in addion to the ones you have, these will do you well for a good period of time to come.....