There's a number of active communities about still playing the game, including /r/alphacentauri on reddit, a discord server at https://discord.gg/7BkcvXUX , and https://alphacentauri2.info/index.php?action=community

I know the last time I picked it up, there were a well respected set of patches from scient (a quick google pointed me to https://github.com/DrazharLn/scient-unofficial-smacx-patch ). Somewhere in here is a pre-done distribution you can just click and run with for modern windows.