If you have pinned too many items to Quick Access and want to reset them, here’s how to reset Quick Access.
*Please note that all contents of Quick Access will be reset.

Do not delete the Quick Access folder normally
When you open Quick Access with “Open in new window”, the Quick Access Explorer will open.

You might think that you can delete Quick Access all at once from here, but…

Do not delete the folder from here.
All files in the folder will be deleted.
Open the AutomaticDestinations folder
AutomaticDestinations is a type of file called a “jump list file”, and it seems to store information about the application, timestamps, and paths to documents, web pages, images, etc. recently accessed by programs pinned to the user’s taskbar.
Open the directory below. Set the following location as the Explorer address.
%appdata%microsoftwindowsrecentautomaticdestinations


This will open the folder “Recent Items” > “AutomaticDestinations”.

Delete all files inside
Select and delete all the contents of this folder.

When you delete a file, two new files will be created.

Quick Access has been reset to its original state!

Summary
Now, Quick Access has been initialized!
Please note that once you initialize it, it will not return to its original state, so consider whether you really want to delete it before deleting it.
Please refer to this.