Unusual code detected by google on my site

Have you created any custom input box on that page?

Yes a bunch of custom input blocks because it is for profile questions and biographies and things like that, but there is no strange html or code.

Not that I am aware of, after trying to signup with facebook, it goes to a page (blank) that I am unaware of... what should it be doing?

What is the url of that blank page. Was new account created after seeing blank page?

I am messaging you on messenger

You may embedded anything from external website to that page or that may happening cause of any block of that page

In google chrome browser open developer tools and check error and warning.