I took an in-person class at Second City Chicago. It was 3 hours per week for 8 weeks, and the class had to put on a paid show at Second City at the end of term -- pretty hectic, and very hands on. It teaches a genre of storytelling called "personal storytelling" (not the same as business storytelling, but the principles are similar) that is popular at events like The Moth.
Storytelling is also seeing a resurgence as a community activity -- if you google "live storytelling" events in your area, you'll probably find some (there are tons in Chicago) though during COVID they are all online so it doesn't matter where you are. These are essentially open-mics -- you can YouTube "The Moth" to see what they are like.
Storytelling is one of those things where you gotta learn by doing -- reading a book can only help so much. That said, there's also a book called Long Story Short (Margot Leitman), which I found helpful. (again only for the genre of personal storytelling)
