The trouble is I am having difficulty adding my XML code to my newly created website
You should be able to edit the necessary files using the cPanel File Manager. Remember to check public_html if the domain is not an addon, as that is the default directory for a primary domain.
The trouble is I am having difficulty adding my XML code to my newly created website
That will depend on the site itself. If it is the primary domain on its cPanel account, the domain will be located in the public_html folder. If the site is an addon domain, you will need to check the addon domain section of cPanel to see where the document root is.
Either way, use the cPanel file manager to find the relevant files if you are having trouble!
The trouble is I am having difficulty adding my XML code to my newly created website
You should be able to edit the necessary files using the cPanel File Manager. Remember to check public_html if the domain is not an addon, as that is the default directory for a primary domain.