Stephen,
Jazz encompasses a huge variety of musical styles . . . ranging from tightly arranged bands and early Dixieland to today's jazz, which usually is more relaxed. Even today's jazz can vary from quite melodic to quite abstract. To say it another way, jazz is at least as varied as "Classical" music. Bach is quite different from Haydn or Beethoven or Stockhousen or Varese or today's composers. Jazz is no different. Some jazz is quite challenging, some jazz is easy to listen to, and there can be great pleasure in any of it, depending on the listener.
Many suggestions you have received here are of performances 50 to 75 years old. These are wonderful but give a limited view of jazz. As much as pop music, or "classical" music, jazz is a living form and continues to evolve.
If you use a streaming service, I suggest you simply explore what is out there, listening to old and new releases, and not being afraid to try different things, even if you reject 75% of them.
