You will actually get a second set of bands once December check ins have access to the system. Both sets will work for everything, they are just sending out a set per reservation right now, rather than one band per person. If you don't customize them they will send you gray bands so go ahead and pick a second color and enjoy!
Just go to Guest Services at any park or Downtown Disney to activate your APs. You shouldn't need to have the bands with you as nothing is actually stored on the bands. They link to Disney's database where your AP information will be. That said, you are probably going to want to use your band for entry so you should have it with you for that.
Oh my! Another one?!? I hope I can get another color, it would be awesome to be able choose between 2 colors to wear!

Thank you for all of your helpful information.

Now I can't wait to be able to make FP+ reservations! So much to learn for this non-techie Grandma!
