Michael

I’m speculating a lot here, so clarify some things for me if I’m way off base.

If you have uploaded WordPress yourself make sure that the files are in the correct directory.

It’s pretty common to get a permissions error(403) when your domain is looking at a directory without permissions. WordPress would automatically have an index.php file with permissions on.

You’re using cPanel. If this is an addon domain, make sure that the domain is pointing to the correct directory
Usually /public_html for the primary domain
and /public_html/some_other_folder_you_specified for any addon domains.

It seems that your cPanel hosting is telling you that you are not using a valid index file for your site. Please make sure one of two things are done.

First. Make sure your site is in the correct directory. If it’s the Primary on cPanel that directory is /home/pixlgraphxrest/public_html/ make sure it’s in public_html

Second. Make sure that in /public_html you have the index.php, or some other valid index file.

Hierarchy below.

If you have more than one default file in a directory, the server decides which one takes priority, and then displays that file. Understanding the order the files are served is key to making sure the correct page displays on your website.

index.html.var
index.htm
index.html
index.shtml
index.xhtml
index.wml
index.perl
index.pl
index.plx
index.ppl
index.cgi
index.js
index.jp
index.php4
index.php3
index.php
index.phtml
default.htm
default.html
home.htm
index.php5
Default.html
Default.htm
home.html

Note: cPanel hosting file structure is case sensitive because it uses Linux.

Finally, and this is a shot in the dark. You’re php version on your new hosting may be too high. Check to make sure what your old hosting php version was and set the new to a close iteration.