The site worked before the move.
THE COMMON CAUSES
Database credentials not updated, or the cPanel prefix forgotten File permissions or ownership wrong after copying A different PHP version A missing PHP extension Absolute paths in configuration pointing at the old server URLs in the database still referencing the old domain Cron jobs not recreated The document root pointing at the wrong directory
DIAGNOSING
Read the error log first. It usually names the problem directly.
Check the PHP version and enabled extensions against the old environment.
Check the configuration file actually holds the new credentials.
FOR A BLANK PAGE
Enable error logging and reproduce. The log names the cause.
FOR 404s ON EVERY PAGE BUT THE HOMEPAGE
Rewrite rules. Re-save permalinks in WordPress, or confirm .htaccess transferred and mod_rewrite is working.
FOR BROKEN IMAGES
URLs in the database still pointing at the old domain. Run a search and replace.
THE METHOD
Change one thing, test, move on. Changing several things makes the cause unidentifiable.
