Hi Colin,
Thank you for writing in, while the moving of folders/files from sub-folder to root can be straight forward, there is another step that you need to do on the database to make sure all www.youngstrainingandconsultancy.co.uk/devsite
will be replaced with www.youngstrainingandconsultancy.co.uk
Please keep a backup copy of your database and install a Better Search Replace plugin, and do the following 2 steps.
1) replace http://www.youngstrainingandconsultancy.co.uk/devsite -> https://www.youngstrainingandconsultancy.co.uk
2) replace http:\/\/www.youngstrainingandconsultancy.co.uk/devsite -> https:\/\/www.youngstrainingandconsultancy.co.uk
The classic find and replace script will not gonna work, so please use that plugin.
You can also follow the Migrate Cornerstone Data from Site to Site guide provided here, but instead of migration, you’re just going to create a new database (with updated URL) for your site, and change the database credentials on the wp-config.php file.
Let us know how it goes,
Cheers!