Hello Drishya,
Happy to hear that you are interested to work on SymPy project. It looks like you have interest in different mathematics fields.
You need to have better understanding of the idea description and go through the last year progress report and discussion as well. it will help you to understand the TODO parts and future roadmap.
I will encourage you to start fixing open issues related to calculus to hands on the SymPy and calculus module code structure. You will surely get good ideas during the fixes.
Keep commttiing :)
Cheers,Skype: shekhar.rajak1