Sure it's easier to start off with one if you've never ridden a skateboard before but you will want to learn those things if you want to:
(1) still be able to ride it when the battery is dead
(2) not hurt yourself if the brakes fail (and Boosted specifically tells you not to rely on them)
I doubt people learn to do that. Even in college with everyone riding longboards, only a small number of people were proficient at pushing, and most did not know how to footbrake.