Workspace Design - For Collecting and Organizing Citations
To identify and delete duplicated references, use the "Find Duplicates" link under the "Organize" tab. EndNote compares the Author, Year, Title, and Reference Type fields when identifying duplicates.
Use the EndNote Click plug-in (see "Getting Started") to help find full-text. EndNote explains all about it here: Click.
If you see that Click access is limited to those who have bought EndNote Desktop software, EndNote changed the policy in early 2021 and made it available to everyone. However, storage of the PDFs using Click is a web-based service with two levels. See the Click guide for more on this.