Hi Rashi,
No sure what you are trying to achieve, if you want to open a Mendix project directory in visual studio code so that you can add custom SCSS styles and than want to compile it to css then you can open the folder by just drag and drop from windows explorer to visual studio code and use Calypso to compile. Once you configure and start Calypso it will start watching your scss changes and compile as soon as you save any scss changes.
I hope I got your question correct else please update your question and add more details.