How to setup form to be a popup in website

Also how to setup form to be a popup in website and to adjust popup display after user is like more than 30 seconds in the site? Is there specific code to add to get popup like this in my wordpress site?

You can easily embed your form to your website so that it can be open as a pop-up. All you need to do is to use the Pop up code of your form: 

1. Select Embed Form option.

2. Then, click on Pop-up.

However, if you need to automatically open the form as pop up when someone visits your webpage, without clicking on a hyperlink, then you will need to use the form source code to apply some workaround using JavaScript. If that is what you need, here is how to get the form source code: How to get your form source code

Also you can follow this guide: How to Auto-popup a Lightbox Form

Hope this will help. Let us know if you need further assistance.