I found my copy at a local pawn shop, but you can also try any game outlet that sells used games. Gamestop/EB Games, Play 'n Trade, etc.
It will depend on where you buy the game.
the old republic is a fiew hundred years before the clone wars
Star Wars: The Clone Wars, is an animated TV series. There are no actual movies on that. The closest you can get is Star War II, Attack of the Clones, but that still won't get you far.
The main leaders of the galaxy