Can you give more detail? Maybe a link to your site or some other way to specify where these changes need to be made?
http://www.caresfoundation.org
HOME page, near bottom.
Button text is JOIN OUR COMMUNITY, DONATE, AND CARES VIDEO
It looks like you’re using the Avada Theme. The theme developer has a short tutorial video on shortcodes for this theme. Shortcodes are how you create and control buttons with Avada. You might not be able to change the font here but that is easy enough with a short snippet of custom CSS.
Give this video a view as well. It goes a little more in depth on how to use the different options available in your theme. Including how to edit buttons.
https://www.youtube.com/watch?v=Nlz6mFJ3qQI
