Hi @Paul_C, thanks for the post
If you will need design help with your actual site, i.e. you need us to look at something, then provide the read-only link
http://help.webflow.com/general/guidelines#how-do-i-share-my-sites-read-only-link
We have some interactive demos that you can open up and play with in the designer, I think you will find this site helpful to bookmark:
Demo: Show and Hide on Click
Demokit: https://webflow.com/website/Demo-Kit
Page: Show and Hide on Click
Folder: Interactive Elements
There are some other pages with similar fade ins, like this example showing a slide in form:
Demo: Slide Down Form on Click
Demokit: https://webflow.com/website/Demo-Kit
Page: Slide Down Form on Click
Folder: Elements/Forms
I hope this helps, go check those out and do not be afraid to experiment. If you create a blank test site, you can test and share that link with us, if you cannot get something to work, and we can take a look at it
Cheers, Dave