Excellent write up, one handy tip if I may be so bold is to prepare a little for the tours before hand.
Many forget how many different muscles we all use while riding any distance hence nagging pains develop quickly.
Experienced riders who perhaps do this very often, are used to the many movements associated with bike riding and can go for miles without any fatigue.
Preparing your body, by gentle stretching, arm and leg swings, slow neck turns, this make the joints more flexible, no matter your ages, it can soon become a vital daily exercise which most people forget.
Good news, as your beginning this journey of journeys, your body will quickly adapt, much like the advanced riders here, and before long any distance will finish with wow! I feel good, we could have gone further.
If you counted the amount of different muscles used while riding you would be really surprised, for instance, looking over your shoulders, side to side at junctions, up and down looking at bike clock functions, and all around you, and with the weight of a helmet and possible ear plugs, intercom, head scarf on. Then there is the lifting of a fully laden bike onto it's main stand takes effort, practise makes perfect.
It all adds up, the constant leg moves on and off the bike, swing up and over the saddle, seated adjustments while riding is important. Shifting body weight on a very small seated area stops soreness building, which many people get from sat on the same spot for hours.
Enjoy your bike rides more when your body is more supple, and a lean mean fighting machine< okay slightly too far, but I am sure you get the point I am making.
Happy adventures.