Hi there! You can change the heading font in Mood by going to:
Design > Customize > Fonts
From there, choose a font from the Headings drop-down list. Looks like you’ve already changed the heading font to Museo Sans.
If there was something else you needed help with there, just let me know!
Also just a heads-up that since your site has a Premium plan, you’re entitled to live-chat and email support, accessible here:
https://wordpress.com/help/contact
You’re welcome to still post in these forums, but those other support avenues may be faster, and you’ll always get a staff reply.