This is a reminder to start with the API of Wordpress.com as CMS only. Here the documentation and here the API endpoint:
https://public-api.wordpress.com/rest/v1.1/sites/<YOURNAME>.wordpress.com/posts
If you need a CDN, the media base URL to use should be:
https://<YOURNAME>.files.wordpress.com/path/to/image.png
Spotted a typo or (likely) a grammar error? Send a pull request.