I’m not sure I’d recommend X/Y to start as others have. I definitely enjoyed it but it was noticeably dumbed-down compared to older games. It’s not as bad as S/M (which was so trivially challenge-free I got bored), but I’m concerned that you might just not be interested. They say that game freak keep releasing games for small children despite the players growing up, so bare that in mind if you find the newer games too easy.

I’m not sure I can recommend R/B/Y to a newbie either, as without any nostalgia they will probably seem incredibly dated. Maybe FR/LG is a good place to start, I hardly played it but it seems like you get the original experience with a bit of polish. I feel it’s better to start with an older game as then if you like it you can continue through them in order rather than going back to something with less features. That said if you think it’s too old and you’re not enjoying it then just skip to something newer!