[Teach-Baby-Chinese] Should I learn Cantonese or Mandarin?

The short answer is Mandarin, because people who speak Cantonese are
learning Mandarin, but not vice versa. Mandarin is spoken by majority
of the Chinese population. It's the official language of China,
Taiwan, and one of the official languages in Singapore. Cantonese is
spoken by people in Hong Kong and southern part of China.