you hve made a good choice already by buying a decent-sized tank for the betta. as for care, you will need gravel, an aquarium light, and most importantly a small powerfilter or other type of adequate filter. bettas are very hardy, but you still need to do water changes every few weeks and feed a specialized betta food. in a ten gallon tank, you have room for a couple tankmates for your betta. i would suggest a small school of rasboras or a couple small loaches. both of these species will most likely not provoke your betta and are native to the same areas as it.
A Long life for a Betta is around 30 months.
you can put a betta in a 54 gallon tank
you can put a betta in a 5 gallon tank
no
Personally, I wouldn't keep anything in a 1.5 gallon tank. Not even a single Betta. I consider 5 gallons to be a minimum for a single betta.
Forever.
one
Take care of it just like a normal Betta. A tank no less than 3 gallons, (15litres) and feed it once a day.
You can fit one betta in a 1 gallon tank, but nothing else.
yes of course! my betta is in a 2.5g and is perfectly fine
A 1 gallon tank could have one betta fish, but you will need to be diligent about changing the water on a regular basis. The smallest tank that should be used, even for a betta, is a 2.5 gallon tank as it at least gives the fish swimming room.
Only 1. Usually a Betta is all that is kept in a 3 gallon tank