How Do I Fix My Blank Dashboard?

Unsure what’s going on. I’ve tried four times, reinstalling WordPress each time.

My domain is on a cPanel server running on a 64 bit CentOS system with PHP 5.6.30 and MySQL 5.6.35. It is secured with an AutoSSL cPanel certificate. I’ve used both Softaculous WordPress installer, and manual installation for both WordPress and BoldGrid. I can download and install the base plugin, which then prompts be to install the editor plugin, so I do. I then run through the First Time User’s Getting Started option, and after it downloads the site and installs the additional required plugins, I am presented with the suggestion to proceed to the Customizer. At that point attempting to access ANYTHING at all in the Dashboard just gives me a blank page, as does attempting to access the front end of the site.

I found that if I deactivate the BoldGrid Ninja Forms plugin (by removing it from the plugins folder) I can then access both the Dashboard and the front end, but still not the Customizer. Deactivating ALL other BoldGrid plugins except for Inspirations still doesn’t give me access to the Customizer. I have NO other plugins active.

The site displays in the front end – https://webportfolio.space/ – but any attempt to access the Customizer just results in a blank page with the following URL in the address bar:

https://webportfolio.space/wp-admin/customize.php?return=%2Fwp-admin%2Fplugins.php%3Fplugin_status%3Dall%26paged%3D1%26s

I’d love to take this for a spin, but I’ve already now wasted more than half a day on a site that I was hoping to have done in that time. Any feedback would be great. Thanks.