There are some good tips here:
The best HomePod tips and tricks for making Siri even more useful
www.the-ambient.com
And then the most important thing, IMO, is to master Siri commands:
Searching for an answer? Here's our table of contents: 1) Getting to Know Siri a Little Better 2) Commands for orga..
www.smarthome.news
Lastly, the forum you're currently posting in is a wealth of information with helpful people here to answer questions:
Home automation, in-vehicle systems, Internet of Things, etc.
forums.macrumors.com
And some personal advice from my own experience:
Internet Speed: If you have weak wi-fi you are not going to be happy. Get yourself a minimum 100/100 modem speed and upgrade your router to MESH. Many issues people have are due to Siri lagging or seemingly not responding to commands, and its usually a network issue.
Apple Music: If you don't have an Apple Music subscription, don't bother. If you do, HomePod is a dream. Set up dozens of custom playlists, find your favorite radio stations, upload your own rarities, you are the master of 45 million songs.
Siri Commands: Especially for Music, learn all the commands. "Hey Siri, play (artist name here) essentials", and "Play the top songs from 1995", "add this song to my favorites playlist", "increase volume 40%", etc. etc.