Hi Janani, welcome!

Here is a description on the mechanics on contributing (setting up a dev environment, using git/Github, etc.): http://docs.scipy.org/doc/numpy-dev/dev/. And this text gives some more background on what kind of things you can contribute and what's expected in terms of code quality, testing etc. (for scipy, but applies also to numpy): https://github.com/scipy/scipy/blob/master/HACKING.rst.txt.

Here are some issues labeled easy-fix, if you'd like to try out the workflow on something relatively straightforward to start with: https://github.com/numpy/numpy/issues?labels=Easy+Fix&page=1&state=open

Cheers,
Ralf