Dear Jeremiah,
As a forum moderator, I am not able to access your account or files to find the presentation for you. My role here is limited to providing general guidance and solutions for users to implement themselves. If the file was stored in your school account that was canceled, contact your school IT administrator promptly. The administrator may still be able to recover the file under the organization’s retention policy. If you don't know who your IT administrator is, please refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support
I truly hope you get your issue resolved swiftly. Please know that even though I can't directly intervene, directing you to the correct, specialized support is the most effective help I can provide from my position. Thank you for your patience and understanding. Please let me know if you need anything else. Wishing you all the best.