Hi Rahul Singh . IMO, you should read the doc and build a POC as a starting process. You have plenty of free online API to play with and create something fun.
You can also read code on Github/Gitlab ... to see others code.
You have the Youtube way where you'll find a lot of tutorials and howTos.
Now, if it's not for work, I won't recommand you to learn AngularJs. You may consider Angular (2+), ReactJs or Vue.js as there are more and more used.
Hope it helped, have a nice one ;) !