If you did not follow along and create the starter template, you can click the download link on this page to download the final version.
You can also clone it from the repo here:
https://github.com/bradtraversy/bs5-simple-starter
Once you download it, install the dependencies with
npm install
Then watch your Sass files with:
npm run sass:watch
Then you can open your project's html page with Live Server or whatever you want to use.
All of the upcoming projects will have their own version of the starter template in the project intro, it will include all of the images and assets for that project.