Gods, where to start? Number 1, you're not alone.
Like you, I began with a limited understanding of Jazz, still have in fact, but I have found stuff around the edges and in other places that at least allow me to enjoy the feeling. And it's such a broad church too, everything from the smoothest of cocktail bar/shopping-centre vibed, laid back until you're horizontal cool stuff, through to what can only be described as a lot of atonal honking that not even the musicians mothers could love. It's played by single musicians/duos/trios/all the way up to swing bands and orchestras (some of which have barely a human or two as members). Unlike some of the most basic rock music it's usually (though not necessarily always) more sophisticated in its structure and requires a higher degree of ability to play/sing (though, again, not always).
If, like me, it's not a natural attraction but something you have to work at then you need to find your own pathways to its enjoyment. My starting points were hearing things like Dave Brubeck's track Take Five, and Glenn Miller's In the Mood on the radio when I was a kid. Not forgetting that back in those days of black and white TV there were plenty of old films (and no such thing as recent movies) from the 30's, 40's and 50's that featured jazz bands and orchestras. Not so much from the 60's though, wholesome bikini clad girls and boys who thought surfing and beaches and twangy guitars ruled that particular time period. And then along came The Beatles.
In the early 70's Jazz Fusion (i.e. Jazz/Rock Fusion) sort of appeared, seemingly out of nowhere, at least that's how it seemed when you lived in Perth. All of a sudden the likes of Mahavishnu Orchestra and Return to Forever and the individual musicians who made up those bands were all the rage. Into this arena also stepped Weather Report, a less frenetic, less virtuosi-centred (and ever changing) ensemble who, after getting a lot of their mainstream jazz predilections out of their system in their first couple of albums, released Sweetnighter, and then Mysterious Traveler, and a while later, Heavy Weather. These and the rest of their repertoire (bar one or two) were genre-leading displays of musical delight. I have to admit that Weather Report are where I usually turn to when I'm in the mood for Jazz. I also have a few Miles Davis albums, much preferring B(itches) Brew over something like Kind of Blue. There's also Pat Metheny, Stanley Clarke, Ben Sidran and a few others among my collection. Some of the greats, John Coltrane, Horace Silver, Art Blakey, Louis Armstrong and many, many more who are essential listening don't even get a look in, and in these days of streaming services where you can vitually listen to anything by anyone, they still barely ever get heard. What can I say? It's simply not possible to listen to, let alone appreciate, everything. When you're finding gold in easy abundance elsewhere (Prog, anyone?) you don't often put down your shovel to scratch away at the less appealing stuff on a hill way, way over there, do you?
There's plenty of well respected mainstream rock artists who have used Jazz and Jazz players as a way of broadening their own horizons whilst opening up "Jazz" to the uninitiated. Two that immediately spring to mind; Joni Mitchell's Hejira and Mingus albums are good starters, as are Joe Jackson's Body and Soul and Night and Day, though they're chalk and cheese to each other. "But they're not really Jazz", I can hear the purists wailing, as they gnash their teeth whilst they recoil in horror. No, they're not, but there's a certain flavouring on them that can be considered a sort of gateway drug. Don't forget, back when it was being made The Doors' Riders on the Storm was derided by their former producer as "cocktail lounge music". You just have to recognise what you like so that once you hear it you can choose to follow/not follow up on it.
I could go on, but I won't.