Browse https://github.com/codespaces/
"GitHub will provide each Free plan account 120 core hours, or 60 hours of run time for a 2 core codespace, plus 15 GB of storage to use each month."
"Verified students get free use of GitHub Codespaces, up to 180 core hours per month, for their personal accounts."
— https://docs.github.com/en/education/manage-coursework-with-github-classroom/integrate-github-classroom-with-an-ide/using-github-codespaces-with-github-classroomCourses about GitHub Codespaces
GitHub Codespaces: First Look | Walt Ritscer
Other options
>>> Google Cloud Shell
>>> AWS Cloud9