After installing NodeJS, you need to set up a starter block plugin where you can build your site. Normally, it requires advanced knowledge of complex development tools to create a development block plugin manually. Luckily, WordPress has provided a solution for you to avoid a messy manual configuration process. Learn how @wordpress/create-block works and how it could make your setting up a block plugin easier.
Resources
Building Custom Gutenberg Blocks: The Definitive Block Development Tutorial