Need help with re-designing an Adobe Muse website

Hey there guys, I recently decided to switch from Adobe Muse to webflow, and I now have to completely re-design some website from my client’s in webflow and I now need help with a few things so first of all, here is the website I am re-designing:
And here is the current progress on the website in webflow:

My 3 questions:
1: On the bottom of the site where the contact form is the background opacity that I set to make the image fade a little bit seems to influence the text and form on top op it, how do I change this?

2: For the form I want the boxes to be next to each other just like on the old site: How do I do this?

3: How do I make the navigation centered like on the old site and sticky?

Looking forward to a response!

Yours Sincerely,