You'll need a filter, heater, and light suitable for a 10 gallon tank. I like fluorescent lights best, especially if you're going to have live plants in your tank. A decoration or plant that gives your fish a place to hide is appreciated by them. Bettas like a varied diet, so I alternate feeding mine brine shrimp, bloodworms, and floating pellets. I feed him small amounts twice a day, and starve him one day of the week. If he looks bloated, I skip a meal or feed him a tiny piece of blanched, peeled pea. Make sure you have water conditioner if you use tap water, and also have water testing supplies to check things like pH, ammonia, nitrates, nitrites, hardness, etc.