First batch of phones will have a delivery of 9/21 with no extra charge.
You will also have a store pickup option listed. You put in your zip and it’ll give you earliest pickup dates and 1-hour time windows (from what I remember) at the locations nearest you. If you’re fast and lucky, you’ll get a time on release day. You might have to pick a store that’s further away if there aren’t times available.
Last year I had to pick Apple stores an hour away from in order to pick up on release day but that was due the Apple store app getting hung up. This year I’m just going to get it delivered.