Node.js is an open source server environment which uses JavaScript on the server to develop backend applications
As you can see the definition itself describes that Node.js is all about JavaScript so your first step to Node.js should be Learning JavaScript
You can use these free resources to learn javascript:https://youtu.be/J4UKL355sUo
Once you are clear with JavaScript then next you can easily move forward to Node.js and its core concepts.
let me also give you some free sources to learn these Node.js Concepts:
edureka Node.js - YouTube
As your concern is regarding how to create restful API lets discuss about it:
REST or RESTful stands for REpresentational State Transfer. It is an architectural style as well as an approach for communications purpose that is often used in various web services development
Let me tell you in simple words: It is an application program interface (API) which makes use of the HTTP requests to GET, PUT, POST and DELETE the data over Web Server
To learn how to build RestFul API, follow this way:
- You should be aware of basic designing principles of Restful API
- You should be able to work with Express.js
- Choose any database, Understand how to perform CRUD operations with it, and try to create a simple API with it
You can also make use of this blog to perform it practically: How to Build REST API with Node.js from Scratch | Edureka
To know more about Node JS, It's recommended to join Node JS Course today.