Even though I was use to our MS, the Model 3 was different enough for me that we drove it to a nearby empty parking lot and checked out a few things before heading home while driving around the lot.
Looked through all the settings so I could set it up as I wanted ahead of time and not be concerned while driving and wanting to change things.
I tried out the different steering settings and regen braking. Made sure the brakes worked as well.
I found the windshield wiper and settings and checked out using the wipers.
Made sure the car's headlights were set to auto (think it's a default but not sure).
Programmed a few radio/music selections to make the drive pleasant listening and checked out the sound system and speakers.
Tried out the turn signals and brake lights (husband stood outside the car to check those worked).
Adjusted the steering wheel, seats, etc to set my profile.
Adjusted the side mirrors and the rear view mirror so that I could see traffic still visible in my rear mirror as it entered into my side mirror (avoid blind spots).
Backed up the car to see how that was using the rear camera.
Pulling into a parking spot was a bit different than our MS and liked the visual on the screen.
Checked charge level and stopped off at a Supercharger to make sure the port and Supercharging worked. You need to have a credit card attached to your account to use it (done through your online account set up).
We brought my new all-weather car mats with us so took out the carpet ones and replaced them with my new ones.
We had my phone set up at the DC so just made sure I knew how to make a call. My husband and I could then be in contact driving home.
Used Navigate on the way home to try it out. If you ask it to Navigate to the nearest Supercharger it will pre-warm your battery so it gets the most efficient charge rate.
Did try to stay away from other cars/trucks to avoid and rock chips but that depends on where you are driving and the time of day.
Think that was about it. The car calibrated for us within maybe 10 minutes but I decided to save trying out the AP for later although many are more than comfortable using it from the start. Enjoy driving and the trip home!
Oh and if you read up and pre-purchased and set up your USB flashdrive for TeslaCam/Sentry Mode on your home computer/laptop--must be formatted with FAT32 and follow proper TeslaCam file set up, install it before leaving. Hate to say I've read about someone leaving the factory after pick up on 580 and being rear-ended within a short distance from the factory. Never know when it could come in handy. Also be familiar with the ins and outs of using it, like knowing it's on, how to pause it so you can safely remove the drive, saving video, etc. Here's a link to the latest manual (10/30/19):
https://www.tesla.com/sites/default/files/model_3_owners_manual_north_america_en.pdf A newer version will probably come out soon as there have been a lot of updates that happened in the last few months. But this should get your started with TeslaCam (search by dashcam I think) and Sentry Mode (search by Sentry).