Hi Patrick!
I'm a theremin newbie too - I've been at it for just a couple of months here. There are many great people on this board and elsewhere. You might want to check out the great workshops that Lydia Kavina offers every Sunday - she's one of the "greats!" She welcomes EVERYONE to her workshops - total neophytes to great thereminists. The workshops, via Zoom are usually attended by people from all over the world (literally) - GREAT fun and wonderful people! Her next one is tomorrow at noon EST (FYI, she lives in London, England but was in Moscow last week). Regardless, check out her site at: http://www.lydiakavina.com/ I'm sure you can still attend tomorrow but you'll need to write to her. Her workshops range from total beginners to advanced, although i attend all of them as it's still possible to learn a lot from her. As you're a musician, it'll be easier for you to understand everything (although playing the theremin is tough - but FUN)!
Also, I've been taking private lessons with her every couple of weeks (wish I could take them more often) and she's also an INCREDIBLE teacher. I believe that Carolina Eyck was one of her students.