Go to WP Menu => Appearance => Customize =>Click on Body Typography
In typography you can see body typography from there you can set font family and size, line height.
Go to WP Menu => Appearance => Customize =>Click on Typography => Click on Heading
In typography you can see Headings from there you can customize the heading tag font family, font size, line height, letter spacing, font weight, font style, text-transform & text decoration.
