Do i need to play the 1st one?
To understand the 2nd one. I dont have BG1, so i am not sure. If it helps, i am familiar with the Forgotten Realms. I read alot of fantasy novels, mostly R.A. Salvatore.
In Vietnam The Wind Doesn't Blow, It Sucks
I don't think you NEED to have played the first one, it'd help because you'd get certain references and stuff but you're not missing anything vital.
The first game was very good, by the way. So you may want to buy it for that reason...