yes you do and a filter the tank needs to be atleast 5gallons with plants and places to hide. with the right setup siamese fighting fish(betta fish) are very easy to lookafter.
not really, everyone i know an my own fish have all been in glass bowls or small tanks that arent very big at all. as long as you clean the tank every week,use s water conditioner and have pebbles at the bottom it should live fore more that 8 months