HI c'
Check to see if you have Type Embellishments one LET installed. It produces the characters shown below for the alphabetical characters A to Z and a -to z.
Below that are shown the first characters displayed in Fontbook for the fonts listed beside the character.
Each of these is labeled Glyph 4 within the set and mapped as unicode U+F021.
U+F021 is well into the "Private use" area of the Unicode character table—an area not generally accessible from the keyboard, and for which very few characters are visible in the Character Viewer (aka 'Emoji and Symbols).
You can, though, view these characters in Fontbook, and drag them from there into a Pages document, as i did for the screenshot above.
Several of the Zapf Dingbats characters are displayed in the Character Viewer as well, and can be dragged from either Font Book or the Character Viewer into a Pages document.
Regards,
Barry