As for attachments on emails, they don't (even for a 100% online highschool). To turn in a paper they can just hit "share" and select their teacher.
Files and filesystems are almost dead to them. There is a little hope... My son googled to learn why a game was going slow and answers indicated he should delete the temp files. That was his first experience needing the file explorer.
As someone who grew up with DOS and turned in CS homework on a floppy disk, it is almost hard to watch.
(Cue Doctorow links to enshittification and war on general purpose computering.)
If you're not used to thinking in terms of files, it just looks like a list of your most recent documents, with a search bar to find anything else.
Source: was until recently a classroom teacher for 7-10 year olds.