I will recommend "Final Fantasy VII".
Firstly, I'm much less experienced than anyone who posted here, but I don't necessarily believe that is a bad thing: you see, back in 2019, I was in the same situation as you and the first JRPG I've ever closed was "Final Fantasy XV" (I know, aaaaai know... I know; Iknow).
I've a way of approaching the medium in which, sometimes, I start games planning on playing just 30 or 45 minutes, hoping to see what it is about (I prefer that than watching videos or reading stuff, I feel that I remember more in the long time) — doing that was my demise with "Europa Universalis IV" and "FFXV", for instance.
I’m telling this story because I approached a lot of the mentioned games with that method, mostly feeling good, but it was “FFXV” which got me hooked (zoomer problems, probably).
That said, three months after (25/11/19) I've finished "Final Fantasy XV" (I really liked it, but I'll not recommend it), I started "Final Fantasy VII" because it is, undoubtedly, the greatest JRPG ever (I'm not saying the best, but I'll get there).
Gameplay-wise, it is balanced: I don't feel there are to many or too little random encounters (starting with "Chrono Trigger" can make you uncomfortable when pursuing other games, starting with "Final Fantasy X" will make you want to smash your head on the wall); the game is not hard (even if it has harsh side bosses, the main bosses are temperate — the final boss could be a little harder, it is kind of easy); you don't have to grind, you progress as your journey goes (that is important for newer gamers: when I played "Final Fantasy X" last year I wanted to destroy my "PlayStation 4"); it has more items and abilities than “Chrono”, which feels more basic; the downsides are the “materia” system (it is really fun, but it is, as far as I'm concerned, not the staple JRPG experience) and “ATB” system (then, again, it is not necessarily bad, but it is a “Final Fantasy” thing.
Story-wise, it is dope: if you know what we know everyone knows, it will not make difference (it did not make for me), but if you don't know what are everyone is supposed to know, stop using internet know and go play before anything happens.
Graphic-wise, it is mediocre: I can relate that, if you are using “Codex”, you can accept things most people would normally dislike — the interface is ugly (but functional); the core of the game is nostalgic (even for those who have not lived the time) and holds well (mini-games and combat animations are ugly as hell, though).
It is not too long, it is not too short; it is not frustrating hard (unlike some sequences on "Final Fantasy IV"); it does not require grind (even though you can grind to face frustrating side sequences); music is really famous (the characters' themes are most famous than many other games' themes); it has better side quests than "Chrono Trigger"...
Overall, if I had to recommend only one JRPG, "Final Fantasy VII" is the one to go.
I will recommend "Final Fantasy VII".
Firstly, I'm much less experienced than anyone who posted here, but I don't necessarily believe that is a bad thing: you see, back in 2019, I was in the same situation as you and the first JRPG I've ever closed was "Final Fantasy XV" (I know, aaaaai know... I know; Iknow).
I've a way of approaching the medium in which, sometimes, I start games planning on playing just 30 or 45 minutes, hoping to see what it is about (I prefer that than watching videos or reading stuff, I feel that I remember more in the long time) — doing that was my demise with "Europa Universalis IV" and "FFXV", for instance.
I’m telling this story because I approached a lot of the mentioned games with that method, mostly feeling good, but it was “FFXV” which got me hooked (zoomer problems, probably).
That said, three months after (25/11/19) I've finished "Final Fantasy XV" (I really liked it, but I'll not recommend it), I started "Final Fantasy VII" because it is, undoubtedly, the greatest JRPG ever (I'm not saying the best, but I'll get there).
Gameplay-wise, it is balanced: I don't feel there are to many or too little random encounters (starting with "Chrono Trigger" can make you uncomfortable when pursuing other games, starting with "Final Fantasy X" will make you want to smash your head on the wall); the game is not hard (even if it has harsh side bosses, the main bosses are temperate — the final boss could be a little harder, it is kind of easy); you don't have to grind, you progress as your journey goes (that is important for newer gamers: when I played "Final Fantasy X" last year I wanted to destroy my "PlayStation 4"); it has more items and abilities than “Chrono”, which feels more basic; the downsides are the “materia” system (it is really fun, but it is, as far as I'm concerned, not the staple JRPG experience) and “ATB” system (then, again, it is not necessarily bad, but it is a “Final Fantasy” thing.
Story-wise, it is dope: if you know what we know everyone knows, it will not make difference (it did not make for me), but if you don't know what are everyone is supposed to know, stop using internet know and go play before anything happens.
Graphic-wise, it is mediocre: I can relate that, if you are using “Codex”, you can accept things most people would normally dislike — the interface is ugly (but functional); the core of the game is nostalgic (even for those who have not lived the time) and holds well (mini-games and combat animations are ugly as hell, though).
It is not too long, it is not too short; it is not frustrating hard (unlike some sequences on "Final Fantasy IV"); it does not require grind (even though you can grind to face frustrating side sequences); music is really famous (the characters' themes are most famous than many other games' themes); it has better side quests than "Chrono Trigger"...
Overall, if I had to recommend only one JRPG, "Final Fantasy VII" is the one to go.