Girls, thank God, milk arrived, we take the breast and refused from fo…

Girls, thank God, milk arrived, we take the breast and refused from formula ? Please look, is it normal that the baby eats with such breaks? (Sometimes he eats for 15 minutes, that's all, then he doesn't want anymore, then he lies down a bit, then he asks again - we feed him, we change diaper, and then we feed him again) When is it better to feed, before or after changing the diaper? (If I don't feed him before, then crying, tantrums, until we pee/change clothes)