Generally, a flash is referencing some kind of update or change in your tune. However, you can also "Flash" other modules that is not your ECM (engine computer).
The dealer should be able to run your VIN to see if you have any outstanding updates for your ECM.
Welcome Matt!
1) Always fill it up with diesel and not gas :D
But seriously, follow the owners manual for maintenance, and have a look at our maintenance section here and it should treat you right. Some folks have some bad luck, but the percentage is still small overall.
Great looking truck!