It is best practice to edit your citations within Zotero. After fixing the citation, it will be correct every time you use it. And because you synced your desktop and your online account, you only need to make the changes in either your Zotero desktop or your Zotero.org online account.
To edit, put your cursor into any field.
Remember to click outside the field to apply your changes.
Use the Style Preview function to check the formatting.
To change the casing of the title, right click in the Title field, and transform the text to the appropriate casing.
For Chicago Notes/Bibliography style, choosing the correct Item Type will help Zotero format it correctly.
For more tips, see the PDF below.
For these source types, use the BOOK Item Type:
For these source types, use the REPORT Item Type: