From the “please note” info in the advance reservation section -
Guests outside of the United States who have purchased D23 Expo tickets will be able to participate in advance online reservations. More information on how this process will work will be shared in the next few weeks.
Re the store lines - most are very long first thing. Mickey’s of Glendale and the
Disney store tended to be long all day. The Dream Store has the shortest lines. If you are there only Friday, I’d get a store pass for either MOG or the Disney store for late morning or afternoon, hit the other of those two first thing, and then fit the Dream Store in whenever you can,