Go to Admin > Appearance > Customize > Colors & Fonts > Typography
Set/Update Fonts as required
Base Font/Paragraph Font: Poppins (Google Font)
Heading Font: Custom Font Butler come with Theme Files NOTE: When changing from Butler to any other font, please change all Headings Font Type for H1, H2, H3, H4, H6, Single Post Heading, and Archive Heading too.
Update other Headings as required
4. Title, Breadcrumb and Secondary Font Family for Some Sub Titles