Answer:
You can get a pet rabbit from an animal shelter, animal rescue organisation, breeder, animal show, or pet store. You can buy all the supplies you need at pet stores and other stores (including online).
You keep a pet rabbit inside an enclosure (like a cage). You give the rabbit plenty of toys and play structures so that it doesn't get bored.
You give the rabbit time outside the enclosure every day for exercise, play time, socialising, and so you can observe its appearance and behaviour for any signs of ill-health.
You give your rabbit healthy foods: lots of hay, fresh water, high-quality pellets, and fresh leafy greens. Non-leafy vegetables and fruits are okay as a treat. That's it for food: all other foods are unhealthy for rabbits, even as a treat.
You bring your rabbit to the vet when it's sick, and for a regular physical exam once a year or so.
You protect the rabbit from danger and stress.
You groom your rabbit (clip the nails, brush the fur - especially when the rabbit is moulting), and give physical exams at home.
See the related questions below for more details and helpful links.