To use forms you can install the Contact Form 7 WordPress plugin or use Jetpack forms feature. After the installation of the plugin just create a new form via the Contact Form 7 settings page and copy/paste the shortcode into a page or post.
If you have already installed Jetpack you can activate the Jetpack Contact Form feature under Appearance → Jetpack and then just add your form via the new “Add Contact Form” button at the top of your text editor field. Here is an example of the Jetpack contact form:
Fehler: Kontaktformular nicht gefunden.