You can't call .all() twice. In myEntryQuery you have converted the result into an array, you are then trying to call .all() again, but at this point you have an array, so .all() can't be used as it's not an entry query anymore.
entries will now be an array, at this point you can loop through this array and output what you need.
This happens when you go from old versions of craft, in the latest versions you have to have the config/db.php file like this:
'dsn' => App::env('DB_DSN') ?: null,
'driver' => App::env('DB_DRIVER'),
'server' => App::env('DB_SERVER'),
'port' => App::env('DB_PORT'),
'database' => App::...