How to start contribution

Respected Sir/Ma’am,

I am Sahil, a computer science undergrad. I really want to start my open source contribution journey, but do not know from where to start. I am aware of c++ and oops concepts, can also code in python and also know _javascript_, HTML, CSS. Please guide me how  I can contribute to your organization. And if I can work under any mentor than that will be very helpful for me.

Hoping to hear from your soon.

Regards,

Sahil