I'm new to Zotero. Trying to add a child note to a file, but when select file and choose "New Note" I only get option for "Add Standalone Note" not "New Item Note." Why is the latter grayed out?
You can only add notes to parent items, not attachments. If you have a standalone attachment, you'll need to create a parent item (or save a parent item that includes an attachment to begin with).
Upgrade Storage
https://www.zotero.org/support/adding_items_to_zotero#standalone_attachments_and_parent_items