When does ur baby speak his first word

Mine also boy. Dont know why they always emphasize on “mama papa” to be the first words. Mine only called us at 15 months. Now 20 months non stop. He started talking 1-3 words around 10-11 months or so. Like ball, bubble. He only actively speak words at 15 months on suddenly absorb very fast and can say alot of words. Now 20 months can tell us what he wants, like milk, snack, carrot, etc. sometimes can say i want to do it, dont want, stop etc. i can only advise to just keep talking to them non stop and read books. Not those alot of words, more to interactive of few words. Just describe whats in the picture.