It seems you're looking for a downloadable PDF of the "Katekisimu Katoliki" which is likely a Swahili translation of the "Catechism of the Catholic Church." The Catechism of the Catholic Church is a comprehensive summary of the Catholic faith, first published in 1992 by Pope John Paul II.
For the Chichewa ("Katekisimu Katoliki") version: katekisimu katoliki pdf download new
Be cautious when searching for "Katekisimu" alone, as many search results link to the Westminster Shorter Catechism or Luther's Small Catechism It seems you're looking for a downloadable PDF
The Importance of the Catechism in the Catholic Faith Episcopal Conference of Malawi – Lilongwe
Vatican Official Archive: The Holy See offers a comprehensive web-based version that allows for easy navigation through the four main parts of the faith.
Here is the practical reality: A fully translated "New Katekisimu" in Chichewa is rare online. Most parishes still use the English CCC or the classic Mafunso ndi Mayankho (Questions and Answers) booklets from the 1980s.