From my experience during the iPhone 7 launch in the Apple Store at Sydney and when the pre-order happened in Singapore.
At the Apple Store, there will be 2 queues. One is for walk-in (usually those who queue for days and another is for those who have ordered online.
Those who ordered online, I believe, can choose for pick up or have it delivered, on launch day.
The pre-order should happen on the same week Friday at 1500 hrs (0000 PDT, San Francisco time) unless stated otherwise. That is when we can order the iPhone and have it delivered or picked up by next week Friday (launch day), unless it gets sold out within the first few seconds or minutes.
However all of which, is still subject to change from Apple.