Fish for beginers in a 1 1/2 gallon tank

Question
I have a small 1 1/2 gallon aquarium for my daughters room. It has a an air filter/ with gravel but no heater.  We have purchased first a Mickey fish that lived for about two or three weeks and died and then we purchased a Goldfish and a tiny frog and put them in together. The goldfish only loved about 24 hours and the frog lived about 5 days.  This time we had filled the tank with distilled water and also added a half- teaspoon of aquarium salt as well as a drop of dechlorinator.  WE floated the fish and frog for about 15 minutes before putting them in.  The first time we did the same thing but used tap water.  What am I doing wrong my three year old is heartbroken that her fish keep dying.  We were only feeding the Mickey once sometimes twice a day and have done the same with the frog and goldfish.  We also really liked the frog and would like to get another if he could survive perhaps even instead of the fish.  I was not a fan of the goldfish as he just seemed to big for our tank is there something like a guppy that we could put in there.?  Thank you for your help I just hate to keep having my daughter's heart break over her pets.  
Rachel

Answer
Hi Rachel:  The tank has to cycle before you can add fish.  Go back to the aquarium and ask them for a product to help your tank cycle... in fact its called cycle.  You will also need an air pump and air stone... so that the creatures you put into your tank can breath.  You also might want to consider a ten gallon tank... because the larger the water volume the easier they are to take care of... mostly.   Hope this helps... dave