>>96090898
Read 3e core and get a feeling for it, then whatever stuff you really like read the 2e equivalent to get some juicy headcanon ideas. Then after you've played a few games go back and read the 1e version to see how it was originally conceived and this will all help coalesce what you want the game to be.

Mechanically 3e is the best version, but it has lame plot so once you're familiar with how it runs spend some time in the archives soacking up the better, funner, more dramatic, sillier, more heartfelt stuff from previous generations.