ruchitha2864-afk/MERN ? reverse-engineered prompt

Build me a very simple MERN starter app that shows a basic Hello World style page and proves the whole setup works end to end.

I want something clean and easy to run, with a small frontend and a simple backend connected together. The page should load from the app, and the backend should have at least one route that returns a friendly message so I can tell the server is working. If it makes sense, include a tiny example of saving or reading one piece of data so the project feels like a real starting point for a MERN app.

Keep it beginner friendly, with clear setup instructions in the README, and make sure it runs without extra hassle. If you need to check current docs online for anything, go ahead.