In order to get Magic Bands you have to be staying at a Disney resort that is currently part of the MyMagic + testing. You can't just get Magic Bands if you have tickets.
And if you *are* staying at a Disney resort, make sure to go into My Disney Experience and link them to the profiles for you and your family. Then they'll be linked to the Bands when you eventually are able to get them.
(Linking your tickets also allows you to make your FP+ reservations)
I'm staying at OKW next month and got a letter from Disney asking if I would like to participate in the trial of Magicbands. In the letter it gave me a reservation number that I was able to link to MyDisneyExprience and start planning my trip/fast pass choices. I got the wrist band a few days later and it is very cool, it came in a neat presentation box with my name on the box and band. I think at this point the bands are only by invitation by Disney as they are currently still in test mode so just having tickets or evening staying at Disney will not do.
We're staying at AoA in October and MagicBands just appeared in My Disney Experience. We got to customize them and they mail them right to the house before our trip. exciting!