It’s easy to listen to podcasts on a HomePod. There are hundreds of thousands of free podcasts to choose from.
How to listen to a podcast. Say, for example, “Hey Siri, play the podcast Myths & Legends.”
How to subscribe to a podcast. Say “Hey Siri, subscribe to this podcast” to add it to your library. When new episodes are available, they appear in Listen Now in the Podcasts app on your iOS device and Apple TV.
How to change the playing speed. Say “Hey Siri, play this faster,” or “Hey Siri, play this slower” to listen to news and podcasts at a pace you’re most comfortable with.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)