You can upload files to your hosting account through the "File Manager" in your cPanel control panel. Click on "File Manager", and then scroll down to the directory you want to put the files in.
You can also use an external FTP program to upload files. You have to create a FTP account to do this. Go to the FTP Manager and create an account with access to your public_html directory, then use your external FTP program to upload your site's files to that directory.
