How to start contributing?

[ISHA DESAI]

Respected Sir/ Madam
I am Isha Desai, a computer science student studying in VESIT, Mumbai,
India. I am quite familiar with python, java and c++, but am not very well
acquainted with open source contributions. I wish to be a part of the
Google Summer of Code to broaden my horizons, to learn as well as
contribute to the organization.
Will you please guide me regarding the procedure to apply for GSoC?
Regards.
Isha Desai.