Welcome to GW2F, Quoth! And welcome to GW2! Great game. I really like the thief. Great damage, lots of fun! If you're confused about the lore, you are not alone. I've met folks that didn't play the first Guild Wars (like me) that find the lore confusing. My best advice is to read up on it in the wiki, read the fiction novel series based on Guild Wars 2, and/or read the excellent summary on the lore in the GW2 strategy guide. It might help if that's what has you confuzzled.
Welcome to the forums! You're not alone in being confused by this game. Lots of people are. That's because it's quite different from other MMOs out there. If you have questions, feel free to ask...we love questions. Sometimes we even have answers. lol