Thanks for your message, I would be happy to assist you with this. You can change your heading fonts by going to Online Store>Themes>Customize>Theme Settings>Typography and changing the font under the Headings area:
It is important to keep in mind that this will change the Heading font store-wide, however, this is intended as different fonts per product page/collection page may be an aesthetically off-putting choice for customers who visit the shop.
I hope this helps you out, please feel free to reach out to me if you have any questions at all, we are always happy to chat!