You shouldn't really worry about the 'storage' folder — Zotero manages that for you.

If you have duplicate attachments in Zotero itself, you can delete those items and empty the trash. There's not currently any automated way to do that, though current versions of Zotero will automatically delete identical PDFs if you merge duplicate items. But you can just click an item and press + to expand all items and scan the list for duplicates.

The folder names you gave don't appear to be actual items in your library, so I can't tell you anything about those specifically, but you can paste them into the search bar in All Fields & Tags mode in the root of each of your libraries to see the attachments in question. Note that attachments will also appear multiple times if they're in different libraries.

If you really do somehow have orphaned folders in the 'storage' folder, you could delete those if you were really concerned about disk space, but we don't generally recommend worrying about that, since there's the potential of deleting actual attachments by accident. A future version of Zotero will likely try to clean up orphaned files automatically.

Generally, though, worry about what's in Zotero, not in the 'storage' folder.

Folders in 'storage' that are actually orphaned don't affect your Zotero Storage usage.

Again, you should share the actual folder names so that we can check your library. In normal usage you should never have orphaned folders, so this isn't just something you should go in and do without figuring out how it happened. You should also look at the creation dates of the folders.