Accidentally deleted files from iCloud and trash can

There is almost certainly no way to retrieve these files. A trash can exists to recover files in the event you deleted them accidentally. Emptying the trash means you have taken the additional step of knowing the files in there can safely be deleted.

There is a tiny chance you might still have the files if they're the right type. Photos, for example, might still be in the "Recently Deleted" area. But the chance you can recover your files is miniscule.