Click Files to load up the file explorer in vaultbox:
(Note that the folder structure is just a suggestion - you can create, rename or delete any folder)
To upload a document, go to the relevant folder then click Create new then Upload.
Enter the details of your upload. tags are a way of classifying your uploads, and can be used to specify search terms later. For example, tag everything related to your time in Japan with 'japan'.
Once saved, you can now click on the item in the file explorer to see the details: