That was it, we created a simple form. If you want to add other fields (single choices, multiple choices, textareas, dropdown lists) to the form, you have to add them to the script. If spammers start to automatically fill your form with garbage, you can add a Captcha image verification. If users mistype their emails, you can add form validation. If you want your visitors to send you files with the contact form, you can let them upload files with the PHP contact form.
All these features can be implemented in PHP, but they require advanced knowledge of PHP. An easier solution would be to use 123ContactForm free PHP form generator, which offers all these features and many others. Don't hesitate!