What is the best JS library

It's depend on you. For what you want to do. like me for UI react.js is best.

p5 and React for me

I think it's angularJS.

I think so,but for beginners angularJS is very good

By the way do you like this code: https://code.sololearn.com/Ww5upon1nM8c/?ref=app

I really like Angular 7, I used to use AngularJS