That's one of the reasons they'll usually tell you what version of Blender the tutorial/course was made with, so you can match versions. Most of the time, though, old tutorials will still work (or mostly work) as long as a feature hasn't been removed (in favor of a better feature). Often, what you're looking for has just been moved and/or renamed and/or given a new keybind. The more advanced the course, the more likely you are to run into these issues. (For example... when HUMAN came out, shortly after a new version of Blender came out that completely redid the hair system. The concepts Kent presents in it still more or less work, but the way you do it is almost completely different to how it's presented in that course.)
