Study is right at least a third of the exam has little to nothing to do with piloting a drone. Not a difficult exam just the wording of the questions is... shall we say.... unique.
I was just reading that registration could be done online, I take it this not the case. If I understand correctly, drones under 250 grams need no registration. Check the info here: Master List of Drone Laws (Organized by State / Country) l UAV Coach
I am a complete noob, I only have about 6 hours in the air. My bebop is registered and I have passed the Transport Canada drone pilots exam. Thus certified... as a drone pilot. Still getting my feet under me, so to speak.