Brief, no story spoilers.

My most recent playthrough of Kingdom Hearts (Re:)Chain of Memories was on the PC port via EGS. Any version of the game, but especially PC or an 8th/9th generation console version (except for Switch) will be the best way to play Re:Chain of Memories. As far as I know, the PC version is stable, unlike the unfortunate fate of the sequel. The 1.5/2.5 versions add bonus content to this game if you watch the 358/2 days cutscene movie built into the game, which I wouldn't recommend for first time players.

With all that being said, I most highly recommend that, for your first time, you ignore all of the above information, and instead play the original GBA version, Kingdom Hearts: Chain of Memories, in whatever way you fancy. Why?

To put it simply, Chain of Memories felt that it was tailor made for that 2D format, and the direct translation of the gameplay to 3D introduced a lot of awkwardness to the game, it often feels like it is also slowed down to accommodate for these changes in a way I don't necessarily like. Re:Chain of Memories, as a result of this, feels like it lasts a lot longer than it should, and in turn pads out a game that will likely get stale a bit before you reach the end. While a lot of the bonus content in Re:Chain are cool, they really feel like they only spice it up if you have already played the original game, which makes Re:Chain more suited to replaying after the first time, in my opinion.

With that being said, this game is quite significant in the story, and as many will remind a new kingdom hearts player, there is no such thing as a spin-off! One of the aspects that is the most obvious improvement over the GBA version is having much better cutscenes, since the Playstation 2 is obviously much more capable of storing video than the Gameboy Advance. It may be worth watching the cutscenes of this game in tandem with, or after, playing the GBA version. Alternatively, since you should be playing this in the eventual goal of playing Kingdom Hearts 2, it is worth watching the cutscenes alone if you don't enjoy the game.

One last thing, I will not spoil it, but Re:Chain of Memories ends with a bonus cutscene that I feel would be better suited to be ignored and/or skipped until after playing Kingdom Hearts 2.

Overall, Re:Chain of Memories is a middling remake of an okay game. I personally like the systems that these games have, but I feel that the brevity of the GBA original makes it worth playing more for a first time Kingdom Hearts player.