Welcome to the community @jayamal. Good to see your interest.
I would recommend you to go through the issue tracker and watch out for some introductory tickets and try to solve them.
Check out expectations from the students , this will surely help you.
Be in touch with the community in all the ways possible.
Read the documentation regarding the project which you are interested in and get familiar with the project.
Once you are familiar with the project and have queries and ideas(which you surely will have! 
) , open up a thread regarding all of the stuff related to that project.
Keep discussing and keep contributing.