Guild wars?

helo~ im planning on playing guild wars 2 when it comes out.~~ and i have a couple of questions@@(never played gw before) Will the world be big? like will there be many places to go.(i just like big games cuz it feels more real to me for some reason) And my secon ques..........is will i need to have played the first games in gw too enjoy and fully understand the 2nd one? or is it a totally seperate game but just the same game name? thanks a load^^