Misinformation and 3 bettas

Perceus- a beautiful blue and red male in a vase. I learned a bit more and got him a ten gallon. Family members convinced me to add in two mystery snails and three African Dwarf Frogs. Sadly, I failed to keep up on water changes...(With family members telling me to do them very infrequently) Needless to say, the only survivor after that half-year was a frog.

Rubics- An orange betta, Rubics. He died by plastic plant, ripping his fins and getting stuck.

Riddle- Shiny black. Started lethargic and died.

At least two of the deaths were my fault...

I have learned better now, but I still think of the three fondly... I know at least that their deaths helped me learn, so perhaps I can save more bettas with time then what I have lost.