I was very fortunate to partake in the National Theatre technical course at the North Wall Theatre in Oxford. While I didn't do much with the audio there as it was mainly playback through Qlab, it was however helpful to learn how to set up Qlab for theatre.
Which I then used my knowledge of, along with learning TheatreMix to manage the tech for a production of Little Shop of Horrors at my old school in Didcot.
At the North Wall, I got to spend some time on ETC ION, which is the standard for theatre. Learning how to program and operate the ION was a crucial step into more theatrical lighting, wheras I'd mostly done live lights on ChamSys before
I was very priveliged to spend a day at the New Theatre in Oxford learning their technical systems, everything from lights, to their sound to their stage management systems
It was my first time using a large-scale Yamaha console, as I had mainly only worked with X32s before this.