I'm sure everyone knows this already, but I went looking everywhere and couldn't find an answer that satisfied. I'm going to spell it out for the next person that comes along wondering.
All of the shipboard activities that can be reserved before the cruise will be visible to you under each day of the cruise after you have reached your registration threshold. So. . . If they say you can register 60 days before the cruise, THAT is when you get to see everything.
So, for that special individual who is on their very first cruise and happen to get concierge level, you have 5 days BEFORE the start of the period to put in an email requesting all the stuff you want, but you have ZERO clue what is available, call your shoreside concierge and ask them. You are paying them a ton of money to keep the secret that you don't know what you're doing.
Even if you have to wait for the ability to do everything online, it's going to be ok.
So for that stranger that's searching for this particular answer, have an awesome cruise.