How do you download your update tools on World of Warcraft?

I was trying to connect to the game and it said "cant establish a connection to downloader and updater" so i uninstalled world of warcraft. I then reinstalled it and now it wont download update tools, It will get to about 20% and just stop and wont load anymore. Im only 12 so i dont understand alot of these complicated answeres. Can anyone help me?