My son is 16 but usually he wants a betta, and HE usually comes home with one, from a place that is not good to buy fish. It has been mentioned everywhere here, Starts with a W. He would take care of it and it would die, because it wasn't very healthy in the first place. But I know he knows how to setup a tank. When I went on vacation 2 summers ago, a fishtank got broken, they say it was the cat, but I always questioned that story

. Anyway my son knew to put in the filter, the plants, the ornaments, the air pump, the heater, everything in the large tub I used to let water sit out for 24 hrs. My other son, older, he did not know to put everything in the tub with the fish. He would have forgot a few things. So my younger son has learned from me over the yrs. Once he gets into a routine, I will put up a schedule of what he has to do on which day, it will be fine. I will supervise while he cleans and changes the water and let him know if something could be done differently or in a better way.
And I know not to put all the fish in at once, too much for the cycle in a small tank. I will get the gourami, then the neons, then the cories. I think it would be to overwhelming for my son for all to be in the tank. He will be impatient and want all in the tank but I will make him wait to teach him the right way. That is the way I did it after I found out that is the best for the fish and the tank, from this forum, when I wanted to start tropical.
It is so funny now, when I was thinking of getting into tropicals I thought it would be much harder than goldfish that I already had. I sure was wrong, the goldfish were alot more work.