Principal pass = C.

means you need 2 C.

In another way of putting it, you did not pass STPM. To put it simply, it is as if you haven't sat for STPM. Your highest qualification is SPM.

You can do jobs that do not need qualifications - service sector is one. You don't need a degree to be a stall manager. So if you're willing to start small, you would be able to climb up eventually. Or you can start your own business, be an entrepreneur.

If you want to further your study, you should probably look at redoing your STPM (if it's allowed), go for Foundations/A-Levels, or go for a diploma.