WordPress Dashboard > Appearance > Customize >click on typography
In typography you can see body typography from there you can set font family and size, line height, letter spacing.
WordPress Dashboard > 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.
WordPress Dashboard > Appearance > Customize >click on typography > Click on menu
In typography you can see Menu from there you can customize the Menu font family, font size, line height, letter spacing, font weight, font style,text-transform & text decoration.