Hi Alexander_Va,
Check your iCloud storage first. If you run out of storage, some of your content may be unavailable or not update until you either upgrade or free up some space. This article will show you various different ways to check your storage:
Check your iCloud storage on any device - Apple Support
Check your iCloud storage on your Mac
1. On your Mac, do one of the following:
* macOS Ventura: Choose Apple menu > System Settings, click [your name] at the top of the sidebar, then click iCloud on the right.
The storage bar shows your overall storage usage.
2. Click Manage for more details.
A list of apps and features is shown, as well as how much iCloud storage they use. The apps and features that use the most storage are at the top of the list. You can click an app or feature for more information.
You did a great job looking for your content on both your Mac and the iCloud website. If your iCloud storage looks good, try to recover your missing files on the iCloud website with these instructions:
Recover deleted files on iCloud.com
On iCloud.com, you can recover files deleted from both iCloud Drive and other apps within the last 30 days, whether you deleted them on iCloud.com or another device that has iCloud Drive turned on. However, you can’t recover or restore files you permanently remove.
If you're still not able to find your missing files, you might check to see if your Mac stored a local copy on your computer. Go to Macintosh HD > Users > [your username] to see if a file named "iCloud Drive (Archive)" exists. If it does, check for your files here.
We hope you were able to find or recover your missing school files! If you were, consider creating an archive of your iCloud content. iCloud is designed to be a syncing service that allows you to access content across multiple devices, but not a backup service.
Archive or make copies of the information you store in iCloud - Apple Support
Thank you for being part of the Apple Support Communities.
Kindest Regards.