Holly seeds are difficult to germinate so, for a potted holly plant inside the home, a cutting can be used to start the plant. Home-grown indoor holly will probably not produce berries because plants are either male or female and must be grown together to produce berries. So, buying a plant with berries already is the easiest way to get started.
For best results, keep in a cool room with access to sunlight. You can always move this plant outside when the season is over and, once well-established, it will make an attractive addition to your garden.