u/AdSubstantial9661

There is a Betta fish at my school that is in pretty rough condition. Tank size is definitely wayyy too small. And he seems to have inappropriate hides. I was given permission to take him in but am new to fish keeping so I definitely want some advice. I was going to put him in a 10 gallon tank, get a sponge filter, and heater. I don't know much about diet so any recommendations are welcome!