Hello and welcome to the forum.
Being new, I'm not sure if you know about cycling or not. If you don't have any test kits yet, I would suggest you get a liquid (more accurate than strips) master test kit so you can test for ammonia, nitrite, nitrate and pH. If you just put the fish in, you will start seeing ammonia (from fish waste) in about 2 days. Ammonia is toxic to fish. Eventually there will be bacteria present that will break ammonia down and transform it to nitrite which is also toxic. You will probably start to see nitrite present in your tank in 4 to 6 days. As with ammonia, bacteria will form to transform nitrite into nitrate. Nitrate is also toxic but only at very high levels and there will almost always be nitrate present in your tank. When you do your weekly water changes, you will lower the nitrates by replacing part of the tank water with fresh water. Once your tank is cycled, the ammonia and nitrite levels should always be 0.
Anyway, enough chemistry lessons for one day. Enjoy the forum. Ask all the questions you want. There are a lot of very knowledgable people who are always more than welcome to share their knowledge to help a fellow fishkeeper. Good luck.
