The Add Bookmark tools allows you to add a bookmark to a page in the PDF.

From the Tools menu, select Bookmarks then select Add Bookmark. Now as you move the mouse inside any page the cursor will show "Click to add bookmark" to indicate that clicking on a location in the page will set the bookmark to jump to that location. Clicking on a page will show the add bookmark dialog

Bookmark at top of page
Select this to set the bookmark to jump at the top of the page. Otherwise, it will jump to the specific location in the page.

Bookmarks Window

Existing bookmarks and bookmarks added are shown in the Bookmarks window. Clicking on Add Bookmark will automatically show the Bookmarks window. To just show the bookmarks, from the Tools menu select Bookmarks then select Show Bookmarks.