help please :-(

ok so I decided to try out WoW and see what its all about so I downloaded the 10 day free trial. I cant log into the game. Apparently I have no WoW account associated with my battle.net account. Ive been trying for about an hour to figure out how to create a WoW account and merge it with my battle.net account. I've obviusly had no luck.when i try to create the WoW account it keeps asking me for an activation code but I wasnt given an activation code when I signed up for the trial. I tried to go to WoW.com and do the free trial acct on there separately it said my email was already associated with another acct. What am i doing wrong??? And I wanted to download the original wow but when I pull up the game its the wrath of the lich king one... any help would be great. Thank u!!!