There is more information here than you need to get that Zapfino glyph into Pages. Just drag and drop it into Pages from Font Book character view. You can launch the Font Panel (command+T), select the Zapfino font, and from the gear icon, select Typography, and select ornaments.
Everything beyond this point is optional.
For years, the operating system has been installing a selection of iWork fonts that are not in the default font search path, and do not appear in Font Book, or application font menus. One of these TrueType fonts is named:
Type Embellishments One Let.ttf
and it contains the Digit Five flourish (U+F035) that is similar to what you have shown for Zapfino. Once you can see the characters of this font in Font Book, you can drag/drop to add them to Pages, or once the font itself is selected in Pages, just directly enter the unicode (with Unicode Hex Input enabled) as option+F035.
You get this Unicode number when you hover over the character. The System Preferences : Keyboard panel : Input Sources will allow you to add the Unicode Hex Input item. Select Show input menu in menu bar, if you haven't already.
In Finder Go menu : Go to Folder... and enter /Library/Application Support/Apple/Fonts and click Go. You will see a folder there named iWork. Hold that thought...
Launch Font Book, and in the lower left corner, click the + symbol to add a new Font collection. Name it iWork, and press return. Keep it selected. From the Font Book File menu : Add Fonts... . You want that iWork folder from the previous paragraph. This will load the associated iWork fonts into the new iWork Collection, and present a panel of the fonts. Select them, and proceed.
Type embellishments will be at or near the bottom of the iWork fonts list. Click the dot grid icon from the Font Book toolbar to see the individual characters. Drag and drop what you need into Pages.
