Hello Annie,
Thank you for posting this issue on community forum.
That sounds like the form's sharing settings require an organizational email to access it, which is pretty common for schools and workplaces. Since you don’t have a school or work email, the best bet is to contact the person who shared it with you and ask if they can adjust the permissions. They might be able to allow access to personal accounts or send you a different version of the form. If that’s not an option, you might need to use a school-provided email once you’re enrolled. Let me know if things work out for you. Also mark this post as answer if this helps. Sincerely,Walter White | Microsoft Community Moderator