If you ever get a white page on your WordPress, the best way to troubleshoot is to check the apache error log first. It will have enough information about the issue happening now.
In my case, the error was showing as below in the
PHP Fatal error: Uncaught Error: Call to undefined function imagecreatefromstring()
The issue turned to be a package missing issue, i was missing the php gd package. So i ran the below command to fix this issue
yum install -y php70w-gd && systemctl restart httpd
If you are usung webtatic repo, you might need to add the version to the package name.
yum install -y php-gd && systemctl restart httpd