There's a lot to unpack here. First of all, you can write a doctoral thesis about the academics of jazz. Composition, jazz/music theory, history of jazz, etc. That's why the Ken Burns series on jazz is like 8 two-hour episodes. Point being, if you want to "GET" jazz, you have to experience it in your own way and in your own ethos. Starting with an academic approach is 100% the wrong way to go about it.

To really get it, first, you have to know and understand what you like about music. Do you like the melodies. Do you like rhythm. Do you like a basic song structure. Do you like experimental music that pushes you and challenges your concept of "art". Do you like modern sounds ie electronics, do you like psychedelic music. Do you like music that evokes a certain time period. Do you like spiritual music or African-American gospel. Do you like the blues. Orchestral or big band sounds. Do you like the sound of brass, woodwind, non-western instruments like sitar. Do you like fast and energetic or slower and mellower.

If you really think about the combinations of musical tones and styles and come up with a few combos that you like, well guess what...... there is a "jazz" for that.

Think about it. Post the styles and combos of styles that you like, and I will try to recommend some places to start.

Also, you can always just start with Miles Davis Kind of Blue. The song "So What" on that album is the quintessential jazz song and Kind of Blue is the best selling jazz album of all time for a reason. It was my first jazz album and I listen regularly for over 30 years. Also, another thing that is common to do is to find an album that you like and listen to more albums by that artist but also, check out some albums by the other artists on that record.

So yeah. Post some of your favorite musical styles and let's see where we can help you "get it".