There are over 40 traditional (mostly Bantu) languages spoken in Mozambique: https://en.wikipedia.org/wiki/Languages_of_Mozambique
Many old people and rural living people do not speak the official language Portugese. Whereas the people in the cities and higher educated people often do not speak the traditional languages any more.
In Maputo mainly Ronga and Changana are spoken. Both languages are very similar with slightly different pronounciations of words. Here are some useful links for those who want to learn more:
Translators without Borders: Language data for Mozambique
(inlcuding % of literacy of population)
Instagram Page „Xichangana“ explaining some words and phrases
Changana Courses at the CCMA – Mozambican-German Cultural Center