The most basic project you can create using Node.js and Express.js or Nest.js is a simple REST API.

For this purpose, I'd like to suggest you build a book directory, where you would need to create endpoints, using the four most basic methods: GET,POST, PUT and DELETE.

You'd use GET for getting all books or getting only one book by id. With the POST method, you can add a new book to the list. You'd need the PUT method for updating the existing book, and it's evident that with the DELETE method, you will remove the book from the list.

For this kind of application, you don't have to use the database, and for the first app, you can start with data collected as a JSON file.

npm start

npm run dev

router.get('/', (req,res) => {
    res.json(booksData);
});

router.get('/:id', (req,res) => {
    const { id } = req.params;
    res.json(booksData.filter((ele) => ele.id === parseInt(id)));
});

router.post('/', (req,res) => {
    const info = req.body;
    console.log(info);
    booksData.push(info);
    res.json({ message: 'The book has been uploaded.' });
});

router.put('/:id', (req,res) => {
    const { id } = req.params;
    const info = req.body;
    console.log(info);
    booksData.forEach((book, index) => {
        if (book.id === parseInt(id)) {
            booksData[index] = info;
        }
    });
    res.json({ message: `The book data with id ${id} has been updated` });
});

router.delete('/:id', (req,res) => {
    const { id } = req.params;
    booksData.forEach((book, index) => {
        if (book.id === parseInt(id)) {
            booksData.splice(index);
        }
    });
    console.log(booksData);
    res.json({ message: `The book data with id ${id} has been deleted` });
});