Deathbeckons

Zionna, the file you have downloaded is what is called a .rar file, and it needs to be extracted first. You can use programs such as Winrar or Winzip, but I suggest you download 7-Zip. After installing 7-Zip, you can right click the WoW file you have downloaded, select 7-Zip then either extract here (which will extract wow in the folder you are in) or extract files, then you can choose where to extract. After the extraction is complete you should be able to see all the files you need including the realmlist.wtf

Ublock is definitely a must when surfing the web these days, and if you have already downloaded anything malicious you should get Malwarebytes. Install, run scan and remove threats, then you should be good to go.