install extentions in VSC: 
- Live Sass Compiler
- Live Server
- Sass
Create new folder, there index.html
Create new folder "styles" inside
In folder "styles" create file style.sass and type your css code inside (you don't have to use brackets or semicolons)
Click on Watch Sass on the bar on bottom of your VSC (it should open terminal in VSC and give you information about compiling files. Also it should create 2 new files: style.css and style.map) it is supposed to be in 'styles' folder
Add in index.html inside head line: 
It should work :) If not check problems tab in style.sass file