You'll need to access edit mode to rename or delete your bookmarks.
Edit mode lets you edit bookmarks quickly and conveniently.
To enter edit mode, click the Edit Mode button on the toolbar at the bottom of the screen or press Shift+E.
You can now select any bookmark and click Edit.
A modal will appear where you will be able to rename your bookmark (and edit its URL).
When you've finished making changes, click Save.
That's it! You've now learned how to edit and rename bookmarks on your page.
Here's a short video tutorial: