Not Found message after installing and attempting to logon

I just installed SuiteCRM on a CentOS 7 server that runs with WHM/cPanel.

I had one error pop up that said, “PHP Warning: Cannot modify header information - headers already sent by (output started at /home/crmomg/public_html/install/performSetup.php:148) in [home path]/public_html/modules/Users/Save.php on line 490”

It completed the install and invited me to logon.

So I tried.

The resulting page said simply, “Not Found”.

There was nothing else on the page.

Any idea what’s going on?