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 β†’ Jetpack and then just add your form via the new β€œAdd Contact Form” button at the top of your text editor field. Here is an example of the Jetpack contact form: