Some great ideas have already been posted but there are some other things to consider.
The FJR is a fairly heavy machine that has a good amount of power. But less power in Colorado (about 20 hp and 15 ft-lbs) than at sea level. So that makes the right hand a little more forgiving. Besides, as someone mentioned, accident rates in Europe are tied more to rider experience than engine power. I have no doubt that the same is true in America. Engine power is easily regulated with the right hand. It never ceases to surprise me how many people forget that fact. Smooooth, be smoooooth. That applies to rolling on the gas as well as off the gas.
Practice. Then practice some more. That isn't near a fun as riding around but is useful. Find an empty parking lot and do figure 8s and slow speed turns. Use the parking lines as your guide. They don't cause damage if you hit one. Practice maneuvering at idle, using the rear brake and/or clutch to moderate speed. I find that the rear brake used gently is a great way to keep a u-turn slow and tight. I moderate the clutch lever to walk up the driveway while the garage door goes up. At LOW speeds (under 5mph) the front brake gets ignored by me. Get used to how it feels when you need to increase the speed a wee bit, and get used to how it feels when you need to lose a mph or two. Only practice can do that for you. Take things easy. Start with wide turns and gradually move to smaller radius turns. I've never tried it on the FJR, but I can do lock to lock figure 8's on my FZ, which has a higher center of gravity and less torque to grunt it around those slow turns. I can do that because of practice. When you have more skill and confidence, find a deserted road- plenty of those in Colorado- or BIG parking lot and try some braking maneuvers. You will need to know what to expect under heavy braking. It stops FAST and the rear gets light. You have to know what that feels like.
And finally, get some advanced instruction. I am not sure of the forum rules so I won't give anyone a plug in here, but if you pm me, I will give you the name of several people in the area that are excellent at instruction. Not cheap, but worth every cent. In fact, maybe that should be your first step.
Unlike many others in here, I don't think you must downgrade to a small bike that you will not for too long. To me it is very forgiving and gentle. But I may be biased because of other bikes I ride and have ridden. The caveat is this: you must take things slow, practice, and become more proficient before too many miles pass. Without proficiency, you can be riding a 250 Ninja and it won't matter, you chances of wadding it are much better the less experienced you are.
And like so many have said before, ride alone for a long time. 2-up is a very different ball game and riding alone should be mastered first.
Be careful!!
