⬆️ Don't forget about 50h per month limit.
First step as always in npm projects is to install dependencies by executing command npm install.
You can run any file by executing command npm run ts src/echo.ts where src/echo.ts is the name of your file in src directory. There is a sample file there echo.ts. To make a new console application just copy the file contents and use them as a starting point.
This application is using inquirer library, documentation is always the first place where you should look if something is unclear.