If your Microsoft 365 account has been locked, the best course of action is to contact your school's IT support or the administrator responsible for managing Microsoft accounts at your institution. They will have the necessary permissions to unlock your account and assist you with any issues related to accessing your OneDrive data.
Since you mentioned that you applied for a Microsoft 365 Education account through your school, they should be able to help you retrieve your OneDrive data if the account is not accessible. Make sure to provide them with details about the error message you are receiving and any relevant information about your account.
If you need further assistance with Microsoft support, you can refer to the support resources available for Azure Dev Tools for Teaching, which might provide additional guidance on how to get help.
References: