Suggestions on how to approach a design

Attahced are some rough designs I have for my new site. I want the 3 grids to always span the full width.
Just wondering if anyone could give some advice on the best way to setup my document.

I should add where the parapgrpah text expands very long my intention is the 1/3 blocj would be 100vh and stay still while the text scrolled

This site is what I was thinking to model the dev off?
Should I use Vw & VH

I love webflow but I feel like I always lay the wrong foundations so end with poor choices being made.
If some one has a tutorial they think I should watch I would love that also!

I have watched alot I just wanted to see f there was any other feedback out there.

Thanks heaps to anyone who responds :slight_smile: