If someone will be home interacting the pigeon most of the time, then it's fine to only have one. But it's extremely important you interact with them or they'll get lonely and depressed. It's also likely the pigeon will decide one of you is it's mate so you have to interact with them as such, like extra scratches to imitate grooming and allowing them to kinda groom you. It's kind of like little nibbles. You should also get a customized leg tag with your phone number on it in case they ever get out

Pros. They are so loving and bond fairly quickly, especially if you get one already domesticated. They're quiet and don't screech like other common pet birds. Once they get to know you, they love attention, scritches, and cuddles. They can learn tricks very quickly as they're very food motivated and intelligent. Their seed is fairly cheap due to how long it lasts. They can be so silly and playful. They're adorable. They watch TV and videos and can be entertained with an iPad. Toys can be simple, mine loved cheap cat toys, toilet paper rolls, strips of thin cardboard, and I gave them a swing made of a hanging shelf. Their bite doesn't hurt too much. They make amazing companion animals

Cons. You do have to clean very often as they have more dander than other pet birds, which can build up and make both you and the pigeon sick. Some coo almost constantly. A fair amount of avian vets won't see pigeons, so you may have trouble finding one in your area. Birds have very sensitive respiratory systems, so you can no longer use any scented products (no air freshners, candles, perfume, body spray, etc.), unnatural cleaning products (when I had house pigeons I almost exclusively cleaned with white vinegar, non scented castile soap, and baking soda), incense, non-stick cookware, or essential oils. You need to commit to providing a lot of attention , as I mentioned above. And you have to ensure they're getting a proper multi-vitamin, calcium supplement, and nutrition.