Changes to how EndNote displays in the main library window can be made by selecting EndNote X8 > Preferences > Display Fields. Selecting EndNote Defaults will revert to default field settings.
The position of the column headings can changed by dragging the headings.
You can sort your library references by selecting the field headings: Author, Year, Title, Journal etc.

The Layout button
can change the layout of the following panels in the library window:
For a quick search from the main EndNote library, select All References in the My Library pane and use the Search Library box located on the toolbar.

Type the author's family name or a keyword, press Enter, and the matching records will appear on the screen. If you want to search a group only, you can restrict the group by using the drop down options next to the search box.
You can save your whole library, or part of it, as a compressed file in order to make a back-up copy or email it to a colleague.
To save a compressed library file to your USB or other location:
To restore your compressed library file, make sure EndNote is open, find the stored file and double click on it.
Highlight a reference, References > Find Reference Updates.
EndNote highlights the differences in a side by side comparison. You can choose to update the empty fields only, replace all the fields or copy and paste specific information
EndNote will find duplicates of references and allow you to compare them side by side on the screen, with auto-highlights and locked scrolling, so that you can select which one you want to keep. In the menu, select References > Find Duplicates. Compare the records displayed on the screen and select the one to keep by clicking the Keep This Record tab. The duplicate will be automatically discarded from your library.
EndNote can automatically eliminate duplicate references retrieved from an online search. Open the EndNote X8 menu, select Preferences > Duplicates. Tick the box Automatically Discard Duplicates. Save.