Well for that you need to buy (or get some free ones) domesticated pigeons. There's many breeds of domesticated pigeons out there. Racing homer, pakistani high flyers, birmingham rollers, Indian fantails, Santinettes, Frillbacks, are just a few that come to my mind right away (There's 100's of them)
You can buy the birds from a breeder/pigeon fancier. Before getting birds you need to make sure you have proper housing built. A loft to be exact. Depending on how many pigeons you want to raise, make sure there is etiquette room. Make sure the loft isn't drafty, but it is well ventilated. Make sure it remains dry even if it rains. Provide clean drinking water and a mix of seeds as a diet and you can keep pigeons fairly simply. Are you interested in a particular breed of pigeons? For a new commer, there are a lot of very nice people on this forum that will guide you through the process of building a loft and getting you birds too.
Feel free to personal message me if you have further questions!
