Dear Mary Stremmel,
You can set the google font for many html tags in the template configuration.
Please go to the administrator => Extensions => Template Manager => sj_blog => Style Settings tab => Affected Selectors (google fonts) =>
h3.yt-mod-title,
ul.navi div.mega-group div.mega-group-title span.menu-title,
ul.navi div.separator.level2.showdesc span.menu-title,
ul.navi a.level2.showdesc span.menu-title
=>
h3.yt-mod-title,
ul.navi div.mega-group div.mega-group-title span.menu-title,
ul.navi div.separator.level2.showdesc span.menu-title,
ul.navi a.level2.showdesc span.menu-title, h2.itemTitle
Thanks