I'm sorry to hear you're having problems. Unfortunately, I don't have a Mac and I'm not a Spyder developer, so can't help you much there. (Note: I use Spyder on Windows and went to check this Edit menu problem. I just happened to see the whole Edit menu grayed out also here! Lucky me that I never use the Edit menu, only keyboard shortcuts.)
What I can imagine is that Cmd+C or Cmd+V should also allow you to copy/paste much faster, just as Ctrl+C and Ctrl+V allows in Windows. You may also be able to use drag'n'drop: you select the text you want to copy, and drag to where you want to paste it. If you're copying from inside Spyder, you may have to hold the Cmd key to actually copy the text, instead of moving it.
About the course, it may be the case that the course is a bit old, from the time that Spyder was the main Anaconda IDE (it was!). Today Anaconda doesn't "support" Spyder in the sense of "support financially". However, this does not mean at all that Spyder isn't under active development anymore. The guys here are constantly updating it, which is proven by the recent release of Spyder 6. I love to use it, despite some quirks here and there, and have not yet found a better IDE for interactive development. IDEs like Visual Studio Code focus on running-the-whole-script-from-scratch pattern, but I'm very used to running line-for-line or block-by-block, which I find much more useful for exploratory usage and interactive development.
Hope you can fix or work around your problems! Good luck!