As a beginner, what should I play?
Mana Khemia 2. The game is simple to understand while containing some slightly more advanced mechanics that serve to help you understand more about the mechanics of JRPGs, and whether or not you would want to delve further deeper. Final Fantasy X is also a fine option. I recommend steering clear of Final Fantasy VI and Tales of Berseria until you're at least slightly more familiar with JRPGs. But if you're confident, by all means.
Where can I even buy all these games?
Assuming you've read everything, you know more about the world of JRPGs, you should be able to easily pick a game and start playing. And even if you don't want to play, I hope at least you're more enlightened on the subject matter. If there's any other JRPG that interests you that you have no idea whether or not it's worth playing, feel free to contact me, as I probably have the answer to your question.