I would strongly suggest bringing up the history of Fortran only toward the very end of your class as “fun facts” to close out the training.
Starting out your introduction with modern Fortran forcefully as a scalable parallel programming, array-oriented language with focus on scientific and technical computing with strong support for object-oriented and functional programming and portable and modular and structured code design with strong-typing can really captivate your audience.
You can kick off with an example like in this thread: it’s a parallel program using coarrays and as stated in the thread, it packs a lot. Then teach each of the aspects from the latest standard - it’s great that you can now employ something like Intel oneAPI to illustrate all of Fortran 2018 facilities.
Honestly the history no longer matters as much as a game of trivia you might play with your students at the end.
Fortran is entirely modern, as a programming language it can allow modern coding paradigms that most scientists and engineers at any level still fail to grasp fully in any of the other languages they have dabbled with, regardless of their claims. But when they see it in action in Fortran, it can truly be an A ha moment even if they don’t admit as such.
The history of FORTRAN is mostly irrelevant relative to how much can be accomplished with modern Fortran now towards computational science and all the possibilities with it gazing into the future.
It is common for books and training materials and courses to bring up the history and legacy of Fortran right up front or soon thereafter. I advise doing away with that approach.