Hello Haynes,
In this case the permission warning means permissions inside WordPress itself. That probably came about with copying the database.
You’re welcome to change the database prefix. You only have to do that if you have two WordPress installs in the same database.
A few things to check.
Inside the database itself, make sure the site URL and WordPress URLs match the new address.
Make sure the wp-config.php file has the new database credentials, prefix and address listed.
Also double check to see if the database prefix did change.
If you still have access to the original site, it may be easier to start the move over. That can be quicker than troubleshooting.
Let me know if I can help.
Bill