i remember very clearly getting my first 10 gallon set up, the very first fish that went into the tank was a red swordtail, later on we added neon tetras, some cories of some sort, and a lot of guppies that we would breed for fun all the time
I had a 20g tank with 3 goldfish until me and my little brother got tired of them when I was around 8 or 9...they went in the neighbours pond. My first tropical fish were a BN plec and 2 syno frontosus lol