here is a sticky post to betta care
taken from this post is the list of what you would need
Needed Tank Equipment:
-Tank of AT LEAST 2.5 Gallons.
-Heater. The temperature in the tank needs to stay at least at 78 degrees. (remember 5 watts per gallon)
-Hiding Spots:(caves, plants, etc)
-Filter: This is actually not needed, but it helps. Bettas need a light filter with low flow.
-natural/ artificail Light: bettas need natural day/night cycle just like humans
-Liquid Test Kits:
-Access to Air.
- i highly recomend a turkey baster as well
bettas should eat betta food nearly every day of the week but they could occasionally be fed peas, boiled egg whites, misquito larva, and frozen bloodworms/brineshrimp (most common). just keep in mind that these should not subsitute for their betta food as a staple in their diet
hope this helps