Rider: For educational use only. Does this mean I can't use it to code my Unity games and then share that or even sell it?

If you have an educational licence, that's correct, it should only be used for non-commercial purposes, as per section 3 .1 of the licence agreement which you can view here: https://www.jetbrains.com/student/license_educational.html. For commercial development, a personal or organisation  licence would be required.