If you need to add additional functionality to your site, you can do it using the plugin. Here you can order the development of the plugin you need.
It is possible to order 2 types of plugins:
Plugin with widget
Plugin with admin part
Development of a plugin with complex administrative part and has shortcodes for inserting a page. An example of such a plugin is the plugin “WDV One Page Docs“. You can read more about plugin “WDV One Page Docs” and download it.