What is the best practice to manage subdirectories in WordPress?

Good...The WordPress directory manager is something that until now I only saw in the media gallery ...But if you want something, you can have control over the installation of Total WordPress ...In addition to database errors and PHP for free ...

It offers a range of services like PHPMyAdmin, installing WordPress via a script, file manager, whatever you are looking for ... Logging errors and even how you set up email, spam, you can see what space on the disk hard drive and RAM what kind of CPU you are using.

Configure your localhost on your domain from your server ...He's very complex, I mean, he's very complete.

It's Webmin if you are a basic user, now if you are a more advanced user ... I recommend Virtualmim these two implements that can be easily installed and also configured very quickly.It offers a variety of attributes for you to have control of your WordPress.

But it also depends on your hosting ...As they are installed via the command line / SSH, so if you don't have this option in your hosting, it gets a little more complex if you have VirtualMin or Webmin...

I would suggest looking into registering custom post types. You can program those, or use a plugin like CPT UI. You then get a custom link structure that is e.g. example.com/products/awesome-product. This would then be the 'detail' view.

I'm not sure if you have separate order and error pages, but that could be part of the permalink structure in Wordpress as well. You might even setup rewrites for the example.com/products/awesome-product/order and example.com/products/awesome-product/error parts to have a specific page loaded, or the detail view and then have a custom layout based on these url parts.

If you used the product ID's in the old site, you could also create a custom permalink structure have it like this: example.com/products/1. That way you could easily rewrite url's in .htaccess from the old site to the new using just one rewrite rule and regex for the id's