Hi tanak.sources16,
It appears that the 500 Internal Server Error on your website is being caused by the contents of your .htaccess file in public_html. Please could you check this file for any possible errors?
As for the website error, you should be able to gain access to your website's functions by choosing "Add New Website" in the top right, and pointing your new "website" to your /public_html/. This will not interfere with your existing files.
However, you may be more acquainted to the standard cPanel x3 theme, rather than the x10Hosting Basic theme. If this is the case, you can switch between the two themes by choosing "Switch Theme" in the top right corner.
Thank you,
