ive got an issue, i cant download a think because it says my disc space is all used.. ive only just bought this macbook.. i go to disc utility and there is macintosh HD at the top, it says i have no spece under that there is another saying ive usedon 39mb

ive got an issue, i cant download anything because it says my disc space is all used.. ive only just bought this macbook.. i go to disc utility and there is macintosh HD at the top, it says i have no spece, there is another available macintosh HD that i can click on and that tell me i have only used 39GB out of the 500. to make this abit more confusing, the one that tells me i have no space says its type says its a logical volume group, the other with space tells me the .