I wanted to make a blog in pure react js and Nodejs(express,mongodb) . Also i can post code snippets and heading rather than a simple text

If you want to use pure React, you might want to use something like Create React App, or Vite + React. You can pull in a Markdown library like react-markdown to parse blog posts.

I would also recommend using something like Astro (https://astro.build/), which can parse markdown and React natively.