Headless CMS Website With Interactivity

I found a Bootstrap HTML website theme that I want to deployment to a headless CMS. I am BRAND NEW to headless CMS and I know nothing about it. I have only done WordPress for the last 10+ years.

Here is the theme: https://themes.3rdwavemedia.com/devcard/bs5/index.html

The theme has a blog section. Since this is a bootstrap HTML website, I have no idea how I can update the blog section of the website to create new posts.

I need someone to install this theme for me on a headless CMS platform. I don't know what to use. I have tried interacting GitHub with Netlify, but I don't know if this is the correct approach.

I don't know what I'm doing, so I would like to hire an expert to set this up for me!

THE MOST IMPORTANT PART: I want you to make it VERY EASY for me to update the website and publish new blog posts to the website!

Thank you. If you have any questions, please ask.