OK, the dawn is breaking…
Progress Report:
Gary, I was able to install SwitchRes after downloading it from my newly installed Classilla browser (proud emoticon). It looks like a great app, but it doesn't solve the problem. It gives me one more option for resolution which when chosen, makes the format of the image even more of a square (but correct looking) and the black sidebands even larger. It doesn't, as I expected, fill the entire wide monitor with a desktop where the image is in it's right proportion.
I wonder whether that can be achieved with anything other than an almost square old monitor.But bottom line, I'm now connected and downloading and have understood or have resources to solve most of my problems.
I finally understand based on your last message why I'm not able to transfer files from 10.11. Thank you! I will be doing exactly what you suggest once I find a second hard drive and figure out how to get it in there. I have the old disks for most versions of system X, so that shouldn't be a problem. I love the part about being able to transfer files through a network once I have that in place.
Thank you and everyone else who helped me and I hope to be able to reciprocate in some manner one day.
Eduardo