1. A betta fish requires a minimum 2.5 Gallon(1 feet) tank. Not a bowl or wine glass.
2. Best would be a 5 gallon tank to start with along with some community fish like Neon tetra, Ember tetra, Harlequin Rasbora. Avoid nippy fish like serpae tetra Or barbs. Have a nice set of plants borrowed in plantation substrate and a snail (mystery or nerite) to maintain the ecosystem.
3. These are just minimum aspects of keeping a Betta fish. You can go up and beyond (filter/Heater) giving him/her the perfect life it deserves.
4. Most important, female betta and male betta are not tank mates. Keep them together only if you are breeding. (While breeding could be easy taking care of fry is quite tricky, as they grow up to become adult "Betta")
5. Betta sorority won't work on 2.5 gallons. Minimum requirement is 10 gallons. Keep atleast 5-7 female betta. A pair won't do any good. The more the merrier. Of course heavily planted tank
6. Sick Betta, I'm no expert here but i know aquarium salt or cheaper alternative rock salt plays a vital part in healing a sick betta. Please check YouTube videos on healing your sick betta using aquarium salt.
7.that's all. Don't forget the feed and interact with your betta
Adios