What do I do?

Last year my little brother had a fancy goldfish in our 5 gallon he had gotten for his birthday which turned white and he wanted to know why so he went online to TikTok and people tore him apart, calling a literal 10 year old CHILD abusive and gutted him for having a goldfish. I was furious when he gave it away saying he wasn’t worthy of a pet and came home crying. The friend wouldn't give the fish back and it died in a fishbowl. This year I want to get him a proper tank with fish that will not just live but thrive in a 5 gallon which These are the fish I am considering

Tetras, Betas, Guppies, Snails, Mollies, Algae eater, Cory Catfish, African dwarf frog

I have been doing research with him on these fish advice is appreciated