Normally the shows that can be reserved, will show up on planner around the first of month, previous to your cruise. So yours would be Dec 1. Now that has been closest to normal time frame, but my show up a bit sooner or later. I would start looking at website for reservations maybe mid November.
Muster is easy. Sometimes if you hop on ship Wi-Fi in terminal, you can watch it on the app, and then just go check in at muster station when you board.
Also, you may get offered 3 day, 5 day package dinner deals, or unlimited, which also includes lunches at specialty restaurants. It’s all about keeping an eye on your planner, either website or app.