filemanager hide recent

That's a screen of files you've chosen for those notifications. If they show all numbers, it's usually because the file you chose is no longer where it was when you chose it. Just select the file again (you'll only see named ones) for each notification that's all numbers.

As for a lot of files in "recent", use a different file manager. I use CxFileExplorer, and there's no 'recents'. Total Commander is a good file manager, ported from the Windows world. I used to use it there, and I still have it on my phone for mass copies (copy some files in this directory to another one, but not all of them - and I don't want to write a shell script to do it - run it in landscape mode and you can get 2 windows - I use the source and destination, so I can select some files on the left, then copy to the right), but I generally use Cx for day to day things.