If your text field is set to “Rich Text” you can change the font type within the popup area. You can make the font bold, italic, or underline and you can also add bullet points and links. If you want to change the font size, you have a variety of preset fonts to choose from under Font Themes section: Heading 1, Heading 2, and so on. The themes of these fonts are preset within you website's text box settings and you cannot choose any other font size or type unless you change the themes outside of this area, in the font area of your website editor.
If there is not a preset font type and size listed here that you are after, you must set a font type and size to your overall website’s theme–which in turn effects other areas of your site where you have told font sections to use theme fonts.
Remember, you need to do this OUTSIDE of the database section. Select a font box and change the font type to whichever theme you want and adjust it and then hit "Save Theme". ***NOTE: This will change ALL the other fonts you have used under that theme across the entire website, so be sure you are OK with this.***