How to change Sydney (Customized) Slider Title/Subtitle Font

HI. I’m new to WordPress and learning how to maintain my non-profit’s web site. So far so good, but…

I want to change the font and treatments of the Header Slider images’s Titles and Subtitles. I see Body Fonts and Headers Fonts under Appearance/FONTS. Right now I have blue with white outline. Where do I make these settings?

Thanks,
NickS