Move WordPress Installation Within Same Domain

Here’s a reference that should help: https://codex.www.ads-software.com/Moving_WordPress

OK so I copied and pasted the files and ended up with an error when I tried to go to the ap-admin page

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

The plugin WP Clone works great for me.

I recommend using a backup and extract utility like Akeeba backup. https://akeebabackup.com
and Akeeba kickstart.

Once the plugin in is installed you can create a backup of your site and install it anywhere you wish. After extraction the utility replaces the URL in your database to match it’s new location.

OR

you can go into the admin>settings and change the site’s URL there. Then just by dragging the folder from /blog to / you site is moved. BUT you will have to change the site’s url in the database. You can use SearchReplaceDB2. https://github.com/jmandala/searchreplacedb2

Because your WordPress site is already installed in a subdirectory called /blog, you could simply leave it there and move your index.php and .htaccess files into your top level directory. Your current site may be an html site, so you’ll probably have a pre-existing index.html file. You’ll want to change the name of that file to something like, index.html** so that the server won’t recognize it as the primary index file.

Additional configuration instructions are here: https://codex.www.ads-software.com/Giving_WordPress_Its_Own_Directory

Once you’ve moved your index and htaccess files into your top level and updated your index.php file using the following instructions referenced at the abovementioned link:

Open your root directory’s index.php file in a text editor
Change the following and save the file. Change the line that says:
require( dirname( __FILE__ ) . ‘/wp-blog-header.php’ );
to the following, using your directory name for the WordPress core files:
require( dirname( __FILE__ ) . ‘/wordpress/wp-blog-header.php’ );
Login to the new location. It might now be https://example.com/wordpress/wp-admin/
If you have set up Permalinks, go to the Permalinks panel and update your Permalink structure. WordPress will automatically update your .htaccess file if it has the appropriate file permissions. If WordPress can’t write to your .htaccess file, it will display the new rewrite rules to you, which you should manually copy into your .htaccess file (in the same directory as the main index.php file.)

You will then login at your domain.com/blog/wp-admin and your websever will see your blog as your actual primary site and ignore the index.html and the rest of the files that comprised the old site. You’ll want to delete those, but of course download and back them up before you do so for safe keeping. Remember that your old site URLs are indexed by Google/Bing, etc. You’ll want to install a redirection plugin for WordPress and redirect old URL paths to new ones.

Don’t forget to set your Permalinks again either to refresh the .htaccess file in the root directory.

Hope that helps.