I have a bit of a jaundiced view of classes targeted at authors these days. There's such a proliferation of "pay me to make you successful" schemes out there targeted at writers, most of which are predatory. Maybe you'll learn something? Probably not. Also, unfortunately (to my mind), the ones that seem to be the most successful are those that make people feel good without giving them real, helpful advice or tools.
There are good teachers out there, and good advice-givers of other kinds, but the best way to get good at doing anything is to do a whole lot of it. That's why, though I occasionally teach workshops - I really like teaching Master Classes! - I'm mostly mentoring, coaching, and advice-giving through my Patreon. (I know, I know - seems like everyone has a Patreon these days!) Mine is modest in size (and in advice-giving, really) and works mainly to give me a place to offer insights from my experience to people who care enough to invest in hearing from me. We have a terrific, supportive community and I'm really loving it!