I unziped the file and when I reopen it it's empty, i kind of don't understand how to acess the content
It could be that you accidentally extracted each individual file outside of the folder? This is what the contents in your extracted folder should look like:
Otherwise I'm not sure why it would be empty. You could try downloading 7zip or Winrar to extract the file with, rather than using the Windows extract option? Maybe that's what is causing your issue!