I would start with the throttle.
I disagree. I think you should start with the parts that won't kill you. Learn how to access the bikes speed, the switch input, the brake lever input, etc. BEFORE you try to actually control the speed of the bike.
Lest you think I'm being overly harsh, please realize that I have ridden motorcycles over 500,000 miles. My current two bikes and the 2 of the 4 I no longer own have all had cruise control from the factory. I have ridden less than 10 miles with cruise control engaged in all those miles. There are just too many things that can go wrong when YOU are not operating the throttle, even when it is fast and easy to override the cruise control.
The big problem with cruise control on a bike is that it lets you do other things while the computer is controlling the speed, when what you should be doing is devoting your full time and attention to operating the vehicle.
Those 10 miles? Less than a tenth of a mile at a time, while I adjusted a vent or a mirror on the right side.