Don't worry...everyone onsite is "selected" for MyMagic+ now. It applies to your whole party and lets you choose your Fast Pass Plus selections at 60 days out. You will also receive Magic Bands (you can pick the color on the wepsite or App). There are TONS of threads here about it, many negative, but try not to worry about that. Just use the system as best you can.
This system is new and has completely replaced the old paper Fast Pass machines. Also, your Magic Band will replace your ticket and you will use it for everything, including as your room key. It's actually pretty neat, though there have been some glitches with it being so new. Have fun planning out your trip!