Side by side post subscription form

https://app.screencast.com/y0gVSW4QYYCDD

is a pic of what i need to have the code 4. I’m trying to get a form that fIts my Themes subscription form at the bottom of the page. I do not understand how to do it and i do not no CSS. And i am unable to do it in the Form builder. The developer said they can’t help me. Can any1 here?

The page I need help with: [log in to see the link]