Hello,
You can set the H1 in the editor: https://prnt.sc/153kg1d
Please assign the class to the responsive block and set the font styles in the Advanced typography.
You can change the font by means of the Advanced typography option, which allows you to choose the item from a drop-down or insert your custom CSS class. Please navigate to the Theme Settings > Typography > Advanced Typography.
Here is the documentation providing more detailed instructions: https://xtemos.com/docs/woodmart/advanced-typography-settings/
Best Regards