CTA peview issues

I am trying to build a call to action for my site.
These are the issues I am having
1. When I set the height to auto or 500px. It does not change.
2.When I look at the preview, I see some checkered boxes in the background of the form. Is that part of pre-view or is there a way to remove it?
3. When I change button link to a form, it gives me error that the url is too long etc.
My screen views are not similar to the tutorials you have..For instance the visual editor is on top left. My site is
http://tampahomesexpert.com
I have looked and cannot find the resolution. Please advise.
Thanks

https://wordpress.org/plugins/cta/