The oil life counter will run down after a set amount of time, regardless of miles driven. If it's been sitting for a long, long time, you may as well get it changed before the drive just to get some fresh fluid in it and reset the counter. Maybe you can get the dealer to toss that in.
As pewterz said, any Dexos spec oil is fine - the dealer will use AC Delco obviously, which is generally considered to be Mobil. You can read hundreds of threads about oils for your own use in the lubrication forum.
Vary the speed on the highway, try not to cruise for too long at one particular speed - vary speeds or occasionally downshift. Avoid exceeding 4000 RPM for the first 500 miles, per the track prep guide (which has general break in tips). Here's the whole guide, and you can read their advice on page one:
https://my.chevrolet.com/content/dam...tion-guide.pdf
Enjoy the trip home and the new ride.