Build a Wordpress theme

Hello,

I am a new software and website development company. I regularly have small websites to create, and I would like to delegate the development of Wordpress themes (PHP + HTML + CSS + JS, or somethimesjust HTML + CSS)

I need today a simple Wordpress theme.

The goal is to offer the author the possibility of editing the pages by himself.

You create the forst page with Gutemberg,  I will create the other pages and I explain to my customer how to do.

Css have to be made with "grid" and "menu" from bootstrap.

See the screenshots.

1 - The header, with :

- A 'boomerang' shape with the image of the article or page.

- The menu

The header have to be responsive !

2 - The content :

- Have to be managed with "gutemberg editor" (not other)

- The author can add : colums with grey background, images, large columns, etc..

At the same time, I am looking for a trustworthy person to whom I can regularly delegate this kind of project.

I need you to show me examples that you have already done

Thank you