So it’s been over 10 years - life gets int he way sometimes!
Started the cattle drive years ago. Enjoyed it loads. Made some progress, and then life got in the way and now years later I’m wanting to get back and putting my 51 year old brain back to the challenge.
Find a project that drives you and do it. About 20 years ago after a long trip and many photos, I wanted a way to organize and show them on a PC. I found java, bought a scanner and wrote a slideshow program that I still use today.
In 1998 there weren't as many slideshow programs as today. The code is ugly(as first projects often are) and uses AWT instead of Swing or JFX. But it works!
Find some second hand books (save the current stuff for later) and read up.
The official policy of the Cattle Drive has been it never expires, and I think that's still the case. Practically speaking, it's somewhat languished over the years and as far as I know, there are no remaining active students. However, I think you should send a "Purple Mooseage" to Janeice DelVecchio, who nitpicked the first two modules, and she can probably get you re-established. Let me know how that goes!
Also, 51 isn't old.
Tomorrow is the first day of the new metric calendar. Comfort me tiny ad:
Building a Better World in your Backyard by Paul Wheaton and Shawn Klassen-Koop