Our Bikes!

[GeorgeET]

There are a lot of fit systems out there and your comfort and feeling good after a ride will tell you what works for you. Most fit systems are for racing not casual riding.

You keep on saying that you are 60's that's not old, stop thinking you need to act any age. Get in shape ride the bike, go to gym and workout. Take Tai Chi Chuan classes to improve movement and balance. Get in shape to retire.

As per seat adjustment for start you can set the height so that at the bottom of the stroke (ball of foot on pedal) you have some bend in your knew. The seat can be moved back and forth on the rails on the bottom by loosening up the locking nuts, also tilt. You can set the seat so that when the pedal is forward your knee is over the axle. From there after a few rides you can find your sweet spot.
Not many people really use the lower portion of their racing handlebar and most ride with hands on top like you do. That's not so safe or comfortable.

Consider pulling your handlebars putting them in upside down putting the brake levers back on. Than find a comfortable hand hold leaving an extra inch above the levers. You can also buy new handlebars.

I have done this on my bike kind of tri athlon style and find this to be the most comfortable set up for me ever. Better than my mountain bikes straight bars.