Welcome to AA! You should leave it at the fish you have until you are done cycling. Feel free to ask away. Get a test kit, one that tests for ammonia, nitrite and nitrates at the very least. AP makes a good test kit. Here
is an example of it, Canadian site but you can switch to US site. Once you are done your cycle you can get more fish. Do water changes every second day at the very least. Good luck and look forward to seeing you posting on the board.
Oh and Here
is a link to the nitrogen cycle and how it works.