World of warcraft battle chest dvd rom?

i got this 10 day trial to this game and i'm a beginner at this game and this dvd rom is suppose to have world of Warcraft 1 and the 2nd one also considered as an extension pack called burning crusade and when i put it in it says install burning crusade and it does not give me an option to install the first one. The first one is all i want because i want to start at the beginning. Am i confused? what could be wrong?