My suggestion (and it will be different from the others).
Have an external backup drive "in hand".
Can be created from time machine, CarbonCopyCloner, or SuperDuper.
(I prefer CCC or SD... SD is "the easiest" if you've never used an app like that before, and it's FREE to use for this job)
Just before you unbox the new one, update your backup on the old one.
Take the new one out of the box and set it on the table.
Connect the backup.
Open the lid.
Begin setup.
When setup assistant asks if you want to migrate from another drive, YES, you do, so...
"Point the way" to the backup and give setup assistant a little time to "digest" everything.
SA will present you with a list of stuff that can be migrated.
I suggest you just accept the default (everything), and let it go.
When done, you should see your login screen on the new one, just as before.
Good luck.