Creating the form
If you wish to create a form, see this article.
Adding the form
To insert the basic form, go to the Wordpress administration -> Appearance -> Widgets -> Custom HTML.
Drag and drop the widget into the field you wish for the widget to display. (Only applies for basic form)
Copy-paste the generated code into the content field.
Remember to save the settings.
If you have any further questions, you can contact us at firstname.lastname@example.org