Omniglot is a fan-favorite for writing systems. They offer a free, printable PDF comparing Devanagari and Roman scripts for Konkani.
Search "Learn Konkani in 30 Days PDF" on Archive.org, download the file, and complete Day 1. Then write your first Konkani sentence: Mhojem naav [your name] asa. (My name is...) how to learn konkani language pdf