Ghost automatically generates RSS feeds for various areas of your publication.

For example, adding /rss/ to most URLs on your Ghost publication produces an automatically generated rss feed, for example:

If your site is in Private Site Mode, the RSS feed is not publicly available, however, you can retrieve a private RSS feed URL from within Ghost Admin in the Settings →  General →  Make this site private area.

Further Reading

Official Ghost + Custom RSS Integration
Ghost comes with automatic always-on RSS feeds for your site content - but fully supports custom RSS for when you need to add extra functionality!
How to make a podcast RSS feed in Ghost
Ghost includes automatic RSS feeds for your content out of the box, but you can also easily create a custom feed for your podcast with routes and templates.