Any student (over 18, at any university, in any subject, worldwide) can attend the 2020 Esri User Conference, an online event, for free. In previous years, university student registration to the face to face event in San Diego, was about $100.
This year's event includes plenary sessions, technical workshops, user sessions, an Expo, and unique networking events. It will take place July 13-15.
Below are the steps to register. You might want to preview the process via this video first.