The second part of the NEW Superpower RP will run just like the Historical RPs do.
You won't need to know much, certain things will carry over but they will be explained along the way. The only difference is that this RP will be longer than the Historical RPs so you would still want to join as early on as possible since it will not have the handy refresh feature that you get with each new Historical RP.
Plus, the second Superpower RP will be 60 years after the events of the first Superhero RP so there will be PLENTY of room for everyone, new folks included, to mold the world.