How call php function

If the plugin is activated and you want to call a function in a page, you’ll want to make a shortcode in your plugin.

add_shortcode('my-shortcode', 'myFunction');

and in the edit page put [my-shortcode]

Oh, sorry I missed that you wanted it to add function to “page creation”, thought you wanted to include a function into a page. The links Michael posted should help you.