If you didn't import demo content, and still want to have the same contact page and from like in our demo http://mental-wp.azelab.com/contact/
Please follow the instruction.
1. Create new page, and insert content of attached visual composer code in classic mode under the text tab. (content-of-contact-page.txt in attachment).
See a video how it is inserted. contact_page.mp4
2. Choose existing contact form in shortcode, see attachemnt. (see screenshot contact-shortcode.png)
3. Go to contant page, select the form and enter attached code there. (see attachment contact-form-code.png and contact7-code.txt to copy code )
That's it. If to do everything correct you will have the same form. More details how contact form 7 plugin works, you can read in documentation https://contactform7.com/docs/