Dear Yash,
Thanks for your interest. Your background sounds good for
this project.
Before applying for GSoC with Sagemath, you should start
getting a little bit more familiar with Sagemath (especially
things related to symbolic expressions and the fast
callable). You should also try to compile Sage on your
computer and understand the development process
which is organized around
https://trac.sagemath.org/.
A good entry point is SageMath documentation at
https://doc.sagemath.org/
especially "A tour of Sage" and "Developer".
Ideally, you could also start contributing to Sagemath with
smalls patches (if you need advices where to start, feel
free to ask on this list or on sage-devel).
Best wishes,
Vincent