chriskal wrote:
If it’s not necessary for immediate employment learn COBOL or FORTRAN. Go old school.
My dad was an early developer of FORTRAN for the gov. And a little later cobol. It’s all essentially Swahili to me, but it always seems like it would be cool to know and understand if you had the time, aptitude and inclination.
As someone who had to do some fortran at various points for work and then decided to learn python for fun and a possible career change two years ago. DO NOT DO THIS (learn FORTRAN). It is about as useful as learning classical greek or latin, but less interesting;)
If you just want something fun to play around with, as others have suggested, Python. It's all free open source, and you can literally google the answer for any question you might have (stack overflow). Install Anaconda with python and jupyter and you will have an easy to use, free platform for learning.
I don't know if you have kids, but if you do, getting them set up using python in jupyter notebooks, with the PANDAS library (can do data processing in an Excel-like data structure) and matplotlib library (for charts or graphs) for any math, physics, statistics or STEM school work would give them a huge leg up. This seems like the future to me and what I hope high schools would be teaching (but somehow I doubt it).