It's easy bud! Get a 10 gallon aquarium. Fill it with aquarium sand. Fill it with distilled or reverse osmosis water (tap water is high in ammonia, a chemical in fish pee that is harmful to fish. It is converted from bacteria that grows in your sand into something less harmful, nitrite, and nitrite is converted into nitrate, something barely toxic at all. Distilled and reverse osmosis water is easy to get and has no ammonia,nitrite or nitrate. Before you can get a betta, you gotta build up this bacteria so the tank can turn your fish's poop and pee into nitrate so it doesnt get hurt by ammonia. Just add fish food every day (It will decompose into ammonia, your bacteria eat it and grows) You do not need to do the full cycle is bettas are used to horrible conditions at pet stores and can sadly tolerate a lot of ammonia. I would add some fish food ( a few flakes) once a day for three days and then the bacteria will grow enough to support a betta (with other fish you have to wait more, anything is better than a cup for a betta ): Do a waterchange, put the betta in and then you're good. I reccomend adding live plants as they help control ammonia and nitrate, look pretty, and give your betta places to chill in. They just need a decent light (The light in most 10 gallon kits will be good enough, the aqueon and top fin 10 kits are good)