There are so many places you can start to chip in that it's hard to give advice on where to start.
With c and python you can never go wrong.
Learn some basic coding and then download the source of the software you use/like the most and play around with the code.
When you're feeling bold enough you start looking for some of the more easy bugs to fix.
Some projects suggest good beginner jobs like libreofficehttps://wiki.documentfoundation.org/Easy_Hacks#Entry_level_Hacks
ps. You don't need to hack the kernel to contribute to linux.