Moodle itself is free - there aren't 'free' and 'advanced' versions of it. You can download and install it on a web server, or you can pay for someone to host it for you.
If you install it on a server for yourself, then there are no restrictions on installing plugins. If your site is hosted by someone else, then you would have to check with the organisation that is hosting it for you as to what their policy is about plugins.
If you install it on a server for yourself, then there are no restrictions on installing plugins. If your site is hosted by someone else, then you would have to check with the organisation that is hosting it for you as to what their policy is about plugins.
In case you are referring to a Moodle installation provided via the MoodleCloud, then the answer is that no MoodleCloud plan allows you to add custom plugins and themes - https://moodlecloud.com/app/en/
However - as Davo correctly says - MoodleCloud is not the only way to have Moodle installed.