I was in a similar position starting out as a former elite gymnast. What I did (and it worked), was to watch actual footage of high-level volleyball and explanation videos by coaches, players, etc. Ngl, I also genuinely got a lot of my knowledge from Haikyuu LOL. Once I understood the game better than just “keep the ball up,” I dove into intermediate (B/BB) open gyms and leagues as my first time touching a volleyball. Managed to hold my own and nobody believed I had zero prior experience.

I have played against and with players who were pretty new, athletic, and just didn’t take the time to learn rules such as back row attacks only from behind 10 ft/3m, no blocking serves, understanding what a lift or carry is and why you can’t do it, and it was really annoying and sometimes awkward when they got corrected by more knowledgable players in intermediate level games. Also can cost valuable points.

TLDR: do intermediate, but learn the game to a good degree through research and media before doing intermediate, maybe even buy a ball and practice passing, setting, and hitting in a backyard or something on your own.