You can set the default settings for your text font, colour, size and style for the three most commonly used text text formats: Heading 1, Heading 2, and Default font.
These default settings are then applied to the text displayed throughout your website (for example, wherever you have used the Text widget) except for text that you have explicitly formatted locally instead of using the default settings.
Using default text formats helps ensure that all the text throughout your site has a consistent appearance. It also saves you from having to explicitly format text locally throughout your site. It also allows you to change the default settings later to automatically update throughout your entire website without needing to reformat text page by page.
Note that if you change the default formats for your text, this will change the appearance of all text throughout your website wherever the default text format is applied. It will not change text that has been explicitly formatted locally to not use the default formatting.
Whenever you edit text throughout your website and use the Heading 1 or Heading 2 format, this will automatically set <h1> or <h2> tags that are considered useful for search engine optimisation (SEO).
Navigate to Site Settings then click Text.