FFXII takes place the earliest in the Ivalice timeline, FFT and Vagrant Story are last, FFTA2 takes place several years after FFXII, whole FFTA takes place in an imaginary land based on FFXII-era Ivalice. FFT and VS take place ages after a cataclysm that wiped out the other races, but even in the games before the cataclysm each game takes place in a different region, so the connection is loose enough that you don’t need to know anything about any game to enjoy any of them. I’m sure Wolf Kanno can link you to a resource that further elaborates on the lore connections