There are a few ways to move a WordPress site to Joomla. The simplest way is to use a WordPress migration plugin like WPMU DEV.
This plugin will take care of transferring your WordPress site data over to Joomla, including your content, posts, comments, and followers.
Another way is to manually transfer all of your content and posts over to Joomla. This can be time-consuming, but it can also be more accurate if you want to keep all of your content.
If you just want to move your site’s admin area over to Joomla, you can use a tool like Joomla Transfer. This tool will automatically create a new Joomla site based on your WordPress site, including all of your content and settings.
Finally, you can also use a hybrid approach. You can continue to use WordPress as your content management system, but move your site’s administrative area over to Joomla.
This approach is generally the easiest, since it doesn’t require any manual transfer of content or posts.