Hi
@DaniB1234
Have you linked your reservation to the My Disney Experience website? You set up an account, link your reservation and from there you can begin to customise your magic bands and arrange your ADRs and Fast Passes.
Magic bands aren't posted to UK addresses, they will be ready for you at check-in at your resort hotel. If you don't customise your magic bands, grey ones will be waiting for you at the hotel.