You can refer w3school even there explanation is good and easy to understand
The best way is to use it and enjoy it. Code in it
You will learn faster and better is you practice. start a project and use it
So maybe this could be a good beginning for you. And of course this is not the only source for online courses, but simply I didn’t try courses on other sites so I do not want to offer something that I’m not sure of
Excellent free interactive (can run/modify/play with the code examples) textbook with a slight functional paradigm focus. Highly recommended!