Help me understand John Coltrane .... seriously.

I recommend picking up a copy of Ted Gioia's book, "How to Listen to Jazz." I've been a jazz fan for decades, but I still found this book helpful and enlightening.

It's not dense, very readable. As you can tell from the title, it's written for the everyman and it not technical.

https://www.amazon.com/How-Listen-Jazz-Ted-Gioia/dp/0465093493/

Hey I don't get Rap "music", it doesn't bother me in the least.  If you do not like bop or post bop jazz, so what?   It does not make any sense to some people. Others can recognize the structure in the improvising.  They play the notes in the chords around the melody. It is like algebra instead of arithmetic.  Oh they know ALL the rules, and know how to break them. It is not totally random the notes they play. 

Help me understand ART .... seriously.

That is what you are really asking because real jazz is art. And as with any art form it is ok if you don't get all of it or appreciate all of it, as long as you try. Just move on to another artist and come back to it latter. The more you listen to jazz the more you will find yourself gong back and appreciating pieces you previously passed on.

But of all the jazz artists, I'd have to admit that JC is one of the more difficult to "get" and best left for serious listening after one has a better understanding of jazz.

I second other posts about listening to the Miles' albums first; also "Ballads."

Maybe even better would be "Duke Ellington and John Coltrane," the 1962 recording in which each of these great musicians gracefully gave up ground to meet the other in the middle. It might have been easier for Ellington, as he was a gifted accompaniest, able to comp virtually any other style of player. But Coltrane made his real gift apparent in the slower tunes, especially Strayhorn's "My Little Brown Book."

It's true that Coltrane developed a different language on his horn. But that's the norm in jazz...Parker, Gillespie, Armstrong, and any number of others had done the same thing in their time. To really hear what they're doing, listen to slow tunes; it's much easier there.

Coltrane as an artist exhibited more change over time than did most other artists (with the possible exception of Sun Ra).  Certainly much more than Miles.  A lot of people point to Miles as someone who constantly evolved, but his progression was always rooted in what was popular at the time.  Coltrane went beyond that.  Way beyond that.   From straight ahead player with Miles (and Monk), then his first baby steps as a leader, to coming into his own with his classic quartet, to his final sheets of sound/Free Jazz sound.   All different, but all from the same player.  

For someone looking to explore Coltrane, I would start with his work as a member of Miles's 1st classic group- all on Prestige.  Then to Blue Trane.  Then to his collaborations with Johnny Hartman and Duke Elllington.  This will take you from a player rooted in classic hard bop through his initial explorations in expanding standards.  Then take a deep breath if you want to go any further (and for some the above is enough). 

My Favorite Things shows the first manifest example of the direction Coltrane would take.  I consider the title track to be one of the first psychedelic jams, a harbinger of what was to come later in the decade.  His solo is like whirling dervish; in, around, ahead and behind the melody all at the same time.  Try listening through headphones, late at night-  this will probably be a vastly different experience than listening through speakers.   

If you want to continue, then jump into  A Love Supreme.  Know that this album was so influential that inspired the creation of a church congregation in San Francisco.   I'll admit I did not get this track for a long time, until I watched the Spike Lee movie 'Mo Better Blues".  This track plays over a climactic scene of a marriage taking place in twilight, on a Brooklyn rooftop, with lower Manhattan in the background.   The scene is beautifully filmed, with a late in the day technicolor feel to the film.  A Love Supreme is in perfect synchronization with the solemnity of the wedding ceremony, then the obvious joy of the celebrants.

If you are still interested enough to continue, then go for his free jazz titles that continued to push the boundaries of what was possible.