The interface is very simple, so even if you don't have much experience, you won't have any problems getting it to work. To use Anvi Folder Locker, just add items with the 'add' button on the top. There are no limitations to how many folders you can add.
Once you have everything that you want on your list, you'll see a tab beside each option with six different locks for you to choose from: unprotected, which is self-explanatory; hidden, to make it disappear from view; locked, to require a password in order to access it; read-only, to prohibit any edits to your documents; and hidden and locked, to hide a file and prevent access with a special password.
If you want to change the protections for any document, just select or deselect options as necessary, even if you only want to pause it for a few minutes. You can also cancel it by completely disabling the protection, or you can remove files from the list with a single click, limiting outside access to your files.