We recommend you use a FTP client smart ftp is a good client and it's free. You can also login to your cPanel and hit file manager. From there you can access the public_html directory and upload the files you want to publish there.

 

The red marking indicates where you should upload your files. 

 

 

All website files must go into the public_html folder. Your file should be named index.html for this to show up on the main site.