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Would also suggest Moodle. My remote university is using it and while the interface is a bit archaic (= looking and feeling outdated) and many functionalities are almost never being used because of better alternatives (like the chat function or messages), it does have its advantages. You can set up a good work space where students can use the forum, you can interact with them, you can set up learning assignments, upload documents, videos and so on. I think it does its job quite well in the area that it is meant to be used. No live classes, afaik, but those are easily managable via jitsi, for example.