This probably won't work for everyone, but whenever I'm learning or trying out something new and unfamiliar, I always tend to follow the philosophy of "Just jump straight into the deep end and you have no choice but to swim".
So for those thinking of trying out Lemmy/Fediverse. I suggest trying to get your own instance running. It'll get you more familiar with what Lemmy is and how it works (at least on a high level). Its also really rewarding when you get it all up and running, it becomes something more personal to you since you took the time and effort (instead of just clicking sign up on some instance).
But again, that just how I prefer doing things. To each their own.